Progress 06/29/16 to 06/28/20
Outputs
Progress Report Objectives (from AD-416): The overall goal of this project is to identify effective treatments that lead to improved product quality and nutritional value, and to identify the associated genetic elements responsible for fruit ripening and stress responses. Specific objectives are listed as follows: Objective 1: Evaluate and characterize changes in fruit ripening, postharvest nutritional and sensory quality parameters of strawberries due to pre- and post- harvest treatments with selected compounds, UV and calcium. Sub-objective 1.A. Identify effective treatment strategies that delay fruit ripening, improve postharvest nutritional and sensory quality parameters, and extend shelf-life. Sub-objective 1.B. Apply selected effective treatments to commercially harvested varieties of strawberries from different geographical regions, and validate efficacy and applicability of treatment(s) for industry. Objective 2: Identify key genes and signaling pathways regulating fruit ripening and biosynthesis of sugars, acids, volatile compounds and phenolics in response to effective treatments. Sub-objective 2.A. Conduct bioinformatic analyses of global gene expression profiles and correlate results with those obtained for physiological, metabolomic and sensory evaluations and identify candidate genes and signaling pathways that regulate the nutritional and sensory quality parameters. Sub-objective 2.B. Produce transgenic plants/fruits with the increased or reduced expression of selected candidate genes. Determine whether the up- and down- regulation of a single gene may mimic the improved quality traits that were observed in wild-type fruits following treatments. Approach (from AD-416): Locally grown strawberry fruit will be subjected to pre- and postharvest treatments with selective compounds, ultraviolet irradiation and calcium. Selective compounds are synthesized organic compounds, for example, the derivatives of benzoate, which have shown effect on fruit ripening and color. Fruit quality traits including firmness, soluble solid content, total titrable acid content, color and decay, as well as sensory parameters, such as taste, flavor and appearance, will be evaluated. Treatments that enhance nutritional and sensory quality will be further tested on diverse strawberry varieties produced by commercial strawberry growers throughout the United States. The metabolome profiles of targeted fruit phenolics and volatile compounds correlated to nutrition and flavor/ aroma in selected treatments will be analyzed by HPLC and GC-MS to determine which metabolites and pathways are altered. Global gene expression profiles in treated fruit will be analyzed by RNA sequence and bioinformatics analysis. The analyses will focus on genes involved in oxidative signaling, calcium signaling, and ABA signaling, as well as on the phenylpropanoid pathways and genes affecting biosynthesis of sugars, acids, volatile compounds. Stable or transient transformation with silencing or over-expression gene constructs driven by constitutive or fruit-specific promoters will be used to assess the function of specific genes in various aspects of fruit physiology and metabolism, including ripening, sensory parameters, responses to stresses, and accumulation and/ or retention of health-beneficial secondary metabolites from the phenylpropanoid pathway. Quality traits including flavor, color, firmness, stress tolerance, and phytonutrient content will be analyzed in the transgenic lines. This is the final report for Project Number 8042-43000-015-00D ⿿Enhancing Fruit and Vegetable Nutritional Quality with Improved Phenolics Contents under National Program 306 ⿿Quality and Utilization of Agricultural Products, Component 1, Foods. It covers the four year project with the aim to improve fresh produce quality, including appearance, texture, flavor, and nutrition. Objective 1 is to evaluate and characterize changes in fruit ripening, post-harvest nutritional and sensory quality traits, and shelf-life of strawberries due to pre- and post-harvest treatments with selected compounds, ultraviolet (UV) light and calcium. Objective 2 focuses on identification of key genes and/or signaling pathways associated with regulating fruit ripening, and nutritional and sensory quality traits in response to exogenous treatments. In terms of Objective 1, fruit and vegetables were treated with UVB, calcium, ultrasound and microwave during growth stage (preharvest) and after harvest (postharvest). Preharvest UV treatment was done for six strawberry cultivars grown in low tunnels covered with three plastic films which can differentially block the UV transmittance. The results indicated that strawberry genotype was the main factor affecting fruit quality and shelf life. Film type contributed dominantly for fruit weight loss. Films that block different levels of UV significantly affected fruit color, total soluble solids and shelf life. Thus plastic film selection requires consideration of plant genotype differences. We compared the effects of UVB on fruit quality traits and shelf-life at different fruit ripening stages and different storage temperatures. There was little effect of UVB on improving fruit quality of ripened fruit, while the beneficial UVB effect in immature fruit was observed for postharvest quality. Temperature significantly affected the effectiveness of UVB treatments. Higher temperature could facilitate the UVB effect. This information is important for industry how to use UVB to treat strawberry fruits for better fruit quality and longer shelf-life. Four elite strawberry cultivars from different U.S. regions were treated under different UVB dosages and foliar spray of calcium chloride. We found that one mM calcium spray significantly increased fruit total soluble solids, phenolics content, and shelf life as compared with no calcium control. In particular, when UV dosage was over 0.15 W/m2 (UV index 6 or more), 1-5 mM CaCl2 spray demonstrated highest fruit quality benefit for all the cultivars. The UV index for strawberry fruiting season are usually between 5 to 9. Thus this information is important for growers to use calcium spray for increasing the fruit quality and shelf life. We also studied the phenolics changes in broccoli and eggplant in response to temperature, microwave and ultrasound treatment. For example, glucosinolate levels of broccoli microgreens increased significantly after preharvest 10 mM CaCl2 and UVB treatments, while postharvest UV-B radiation showed a minor effect. Ultrasound treatment is effective to activate ÿ-D-glucosidase with potentially aroma enhancing capability. Our results indicate that the simple treatments can significantly boost the phenolics contents. This information will benefit all the consumers to obtain more health benefit using the simple treatments before cook the vegetables. In support of Objective 2, we compared the effects of UVB on the expression of UVB responsive genes and the key genes in the phenylpropanoid pathway and related branch pathways under different temperatures. The gene expression results agreed with the Objective 1 observations of fruit quality traits after UVB treatments. The UVB responsive genes of ripened fruits were less responsive to UVB than the developing fruits. In order to identify new method to control fruit development and ripening, a collection of 10,000 compounds were used to screen their effect on strawberry growth. About twenty compounds showed stimulatory or inhibitory effect on fruit development and ripening. One compound showing clear stimulatory effect was selected for analyzing gene expression changes during fruit development. RNA Sequence analysis indicated that over one hundred genes responded to the chemical treatment. Those genes were related to stress responses, such as abscisic acid action genes, auxin action genes. They can be used as functional markers for industry management and breeding program. Further, two genes affected by the novel compound were used for transgenic studies to confirm their function in plants. It was observed that increased expression of ABI5B or reduced expression of IAA27 promoted strawberry fruit ripening, whereas decreased expression of ABI5B or increased expression of IAA27 inhibited fruit ripening. Analysis of the transgenic fruits at red stage showed that there were no significant differences on fruit quality traits, including total soluble solids, total phenolics and anthocyanins. The results indicate that ABI5B and IAA27 are positive and negative regulator of fruit ripening respectively. They could be used for further genome editing to produce possible new cultivars with reduced fruit ripening and long shelf-life. Accomplishments 01 Microwave cooking increases anticancer compounds in broccoli. Broccoli cooked in a microwave oven produces an anticancer compound, sulforaphane. ARS scientists in Beltsville, Maryland, investigated and found that microwave and low-temperature cooking increases sulforaphane contents in broccoli by about 80%. Using a high-power microwave with a short time was better than low-power microwave cooking. With this information, consumers receive the most benefit from cooked broccoli.
Impacts
(N/A)
Publications
- Lu, Y., Pang, X., Yang, T. 2020. Microwave cooking increases sulforaphane level in broccoli. Food Science and Nutrition. 8(4):2052-2058.
- Jurick II, W.M., Peng, H., Beard, H.S., Garrett, W.M., Macarisin, O., Peter, K., Gaskins, V.L., Yang, T., Lu, Y., Mowery, J.D., Bauchan, G.R., Cooper, B. 2019. Blistering1 modulates Penicillium expansum virulence via vesicle-mediated protein secretion. Molecular and Cellular Proteomics.
- Sun, Y., Zeng, L., Xue, Y., Yang, T., Cheng, Z., Sun, P. 2019. Effects of power ultrasound on the activity and structure of ÿ-D-glucosidase with potentially aroma-enhancing capability. Journal of Food Science and Nutrition. 7:2043-2049.
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Progress 10/01/18 to 09/30/19
Outputs
Progress Report Objectives (from AD-416): The overall goal of this project is to identify effective treatments that lead to improved product quality and nutritional value, and to identify the associated genetic elements responsible for fruit ripening and stress responses. Specific objectives are listed as follows: Objective 1: Evaluate and characterize changes in fruit ripening, postharvest nutritional and sensory quality parameters of strawberries due to pre- and post- harvest treatments with selected compounds, UV and calcium. Sub-objective 1.A. Identify effective treatment strategies that delay fruit ripening, improve postharvest nutritional and sensory quality parameters, and extend shelf-life. Sub-objective 1.B. Apply selected effective treatments to commercially harvested varieties of strawberries from different geographical regions, and validate efficacy and applicability of treatment(s) for industry. Objective 2: Identify key genes and signaling pathways regulating fruit ripening and biosynthesis of sugars, acids, volatile compounds and phenolics in response to effective treatments. Sub-objective 2.A. Conduct bioinformatic analyses of global gene expression profiles and correlate results with those obtained for physiological, metabolomic and sensory evaluations and identify candidate genes and signaling pathways that regulate the nutritional and sensory quality parameters. Sub-objective 2.B. Produce transgenic plants/fruits with the increased or reduced expression of selected candidate genes. Determine whether the up- and down- regulation of a single gene may mimic the improved quality traits that were observed in wild-type fruits following treatments. Approach (from AD-416): Locally grown strawberry fruit will be subjected to pre- and postharvest treatments with selective compounds, ultraviolet irradiation and calcium. Selective compounds are synthesized organic compounds, for example, the derivatives of benzoate, which have shown effect on fruit ripening and color. Fruit quality traits including firmness, soluble solid content, total titrable acid content, color and decay, as well as sensory parameters, such as taste, flavor and appearance, will be evaluated. Treatments that enhance nutritional and sensory quality will be further tested on diverse strawberry varieties produced by commercial strawberry growers throughout the United States. The metabolome profiles of targeted fruit phenolics and volatile compounds correlated to nutrition and flavor/ aroma in selected treatments will be analyzed by HPLC and GC-MS to determine which metabolites and pathways are altered. Global gene expression profiles in treated fruit will be analyzed by RNA sequence and bioinformatics analysis. The analyses will focus on genes involved in oxidative signaling, calcium signaling, and ABA signaling, as well as on the phenylpropanoid pathways and genes affecting biosynthesis of sugars, acids, volatile compounds. Stable or transient transformation with silencing or over-expression gene constructs driven by constitutive or fruit-specific promoters will be used to assess the function of specific genes in various aspects of fruit physiology and metabolism, including ripening, sensory parameters, responses to stresses, and accumulation and/ or retention of health-beneficial secondary metabolites from the phenylpropanoid pathway. Quality traits including flavor, color, firmness, stress tolerance, and phytonutrient content will be analyzed in the transgenic lines. This report documents progress for Project Number 8042-43000-015-00D ⿿Enhancing Fruit and Vegetable Nutritional Quality with Improved Phenolics Contents under National Program 306 ⿿Quality and Utilization of Agricultural Products, Component 1, Foods. Current report covers year 3 of a 4-year project with the aim to improve fresh produce quality, including appearance, texture, flavor, and nutrition. Objective 1 is to evaluate and characterize changes in fruit ripening, post-harvest nutritional and sensory quality traits, and shelf-life of strawberries due to pre- and post-harvest treatments with selected compounds, UV light and calcium. Objective 2 focuses on identification of key genes and/or signaling pathways associated with regulating fruit ripening, and nutritional and sensory quality traits in response to exogenous treatments. Progress was made on all objectives and associated sub- objectives except objective 2B due to critical vacancy. In terms of Objective 1, four elite strawberry cultivars from different U.S. regions were treated under different UVB dosages and foliar spray of calcium chloride. Fruit were collected at 75% red maturity, and their fruit quality traits and shelf-life were compared. We found that 1.0 mM calcium spray significantly increased fruit total soluble solids, phenolics content, and shelf life as compared with no calcium control. In particular, when UV dosage was over 0.15 W/m2 (UV index 6 or more), 1-5 mM CaCl2 spray demonstrated highest fruit quality benefit for all the cultivars. The UV index for strawberry fruiting season are usually between 5 to 9. Thus, this information is important for growers to use calcium spray for increasing the fruit quality and shelf life. We also studied the phenolics changes in broccoli and eggplant after heat, microwave and ultrasound treatment. Our results indicate that the simple treatments can significantly boost the phenolics contents. This information will benefit consumers in obtaining more health benefit from these vegetables using these simple treatments. For Objective 2, we did the transcriptome analysis of strawberry in response to UVB treatment and calcium. We identified 25 putative genes/ functional markers related to strawberry fruit ripening and phenolics biosynthesis. We are preparing the constructs containing the selected five genes and verifying the functions of selected five genes by agroinfiltration. This work has been slowed down because of the critical vacancy and government shutdown. Accomplishments 01 Ultrasound treatment enhances fruit flavor. Free flavor compounds in fruit contribute directly to fruit flavor, not the bound forms that have attached sugars. Bound forms of aroma compounds are odorless and do not enhance flavor. A key enzyme in fruits that removes the bound sugar, enhances the fruit flavor. However, the activity of the enzyme under normal fruit storage condition is low. ARS scientists in Beltsville, Maryland, used low ultrasound intensity and short treatment time to increase the activity of the enzyme (B-D glucosidase), and studied the effects of temperature and ultrasound treatments for improving enzyme activity for potential flavor enhancement. This study shows that ultrasound treatment is an effective approach to stimulate the activity of ÿ-D-glucosidase and can be used by researchers to develop commercial practices to enhance fruit aroma.
Impacts
(N/A)
Publications
- Chen, L., Lu, Y., Yang, T., Lu, Z. 2018. Optimized cultural conditions of functional yogurt for gamma-aminobutyric acid augmentation using response surface methodology. Journal of Dairy Science. 101(12):10685-10693.
- Yuan, P., Yang, T., Poovaiah, B.W. 2018. Calcium signaling-mediated plant response to cold stress. International Journal of Molecular Sciences. 19(12):3896.
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Progress 10/01/17 to 09/30/18
Outputs
Progress Report Objectives (from AD-416): The overall goal of this project is to identify effective treatments that lead to improved product quality and nutritional value, and to identify the associated genetic elements responsible for fruit ripening and stress responses. Specific objectives are listed as follows: Objective 1: Evaluate and characterize changes in fruit ripening, postharvest nutritional and sensory quality parameters of strawberries due to pre- and post- harvest treatments with selected compounds, UV and calcium. Sub-objective 1.A. Identify effective treatment strategies that delay fruit ripening, improve postharvest nutritional and sensory quality parameters, and extend shelf-life. Sub-objective 1.B. Apply selected effective treatments to commercially harvested varieties of strawberries from different geographical regions, and validate efficacy and applicability of treatment(s) for industry. Objective 2: Identify key genes and signaling pathways regulating fruit ripening and biosynthesis of sugars, acids, volatile compounds and phenolics in response to effective treatments. Sub-objective 2.A. Conduct bioinformatic analyses of global gene expression profiles and correlate results with those obtained for physiological, metabolomic and sensory evaluations and identify candidate genes and signaling pathways that regulate the nutritional and sensory quality parameters. Sub-objective 2.B. Produce transgenic plants/fruits with the increased or reduced expression of selected candidate genes. Determine whether the up- and down- regulation of a single gene may mimic the improved quality traits that were observed in wild-type fruits following treatments. Approach (from AD-416): Locally grown strawberry fruit will be subjected to pre- and postharvest treatments with selective compounds, ultraviolet irradiation and calcium. Selective compounds are synthesized organic compounds, for example, the derivatives of benzoate, which have shown effect on fruit ripening and color. Fruit quality traits including firmness, soluble solid content, total titrable acid content, color and decay, as well as sensory parameters, such as taste, flavor and appearance, will be evaluated. Treatments that enhance nutritional and sensory quality will be further tested on diverse strawberry varieties produced by commercial strawberry growers throughout the United States. The metabolome profiles of targeted fruit phenolics and volatile compounds correlated to nutrition and flavor/ aroma in selected treatments will be analyzed by HPLC and GC-MS to determine which metabolites and pathways are altered. Global gene expression profiles in treated fruit will be analyzed by RNA sequence and bioinformatics analysis. The analyses will focus on genes involved in oxidative signaling, calcium signaling, and ABA signaling, as well as on the phenylpropanoid pathways and genes affecting biosynthesis of sugars, acids, volatile compounds. Stable or transient transformation with silencing or over-expression gene constructs driven by constitutive or fruit-specific promoters will be used to assess the function of specific genes in various aspects of fruit physiology and metabolism, including ripening, sensory parameters, responses to stresses, and accumulation and/ or retention of health-beneficial secondary metabolites from the phenylpropanoid pathway. Quality traits including flavor, color, firmness, stress tolerance, and phytonutrient content will be analyzed in the transgenic lines. This report documents progress for Project Number 8042-43000-015-00D, "Enhancing Fruit and Vegetable Nutritional Quality with Improved Phenolics Contents.� This report covers Year 2 of a 5-year project aimed at improvement of fresh produce quality, including appearance, texture, flavor, and nutrition. Objective 1 is to evaluate and characterize changes in fruit ripening, post-harvest nutritional and sensory quality traits, and shelf-life of strawberries due to pre- and post-harvest treatments with selected compounds, UV light and calcium. Objective 2 focuses on identification of key genes and/or signaling pathways associated with regulating fruit ripening, and nutritional and sensory quality traits in response to exogenous treatments. Progress was made on all objectives and associated subobjectives, all of which fall under National Program 306 �Quality and Utilization of Agricultural Products�, Component 1, Foods. In regard to Objective 1, this past year strawberry fruits were treated with different dosages of UVB light. We compared the effects of UVB on fruit quality traits and shelf-life at different fruit ripening stages and different storage temperatures. We found that there was little effect of UVB on improving fruit quality of ripened fruit, while the beneficial UVB effect in immature fruit was observed in for postharvest quality. Temperature significantly affected the effectiveness of UVB treatments. Higher temperature could facilitate the UVB effect. This information is important for industry how to use UVB to treat strawberry fruits for better fruit quality and longer shelf-life. Strawberry fruits were also treated with two novel chemical compounds (derivatives of benzoate) which stimulated or delayed fruit development and ripening. The effective dosages of these chemicals were relatively low as compared to abscisic acid, a plant growth regulator for regulating strawberry fruit ripening. Low levels of these novel compounds relative to efficacious levels of the plant hormone abscisic acid were much more effective in regulating fruit ripening. These results are useful for further dissecting the underlying mechanics on controlling fruit ripening and developing new methodology to improve strawberry shelf-life. In regard to Objective 2, we compared the effects of UVB light on the expression of UVB responsive genes and the key genes in the phenylpropanoid pathway and related branch pathways under different temperatures. The gene expression results agreed with the Objective 1 observations of fruit quality traits after UVB treatments. The UVB responsive genes of ripened fruits were less responsive to UVB than the developing fruits. We also studied the effects of the novel benzoate derivatives described for Objective 1 on gene expression using whole genome RNA Sequence in order to understand the mechanisms by which these compounds influence strawberry fruit ripening. The putative key genes affecting strawberry fruit ripening were identified based on bioinformatic analyses and quantitative PCR. Verification of the function of a few selected genes in fruit ripening are under the way. Accomplishments 01 Preserving broccoli microgreens with preharvest CaCl2 and postharvest UV-B treatments. Glucosinolates (GLS), are a class of phytonutrients which are beneficial to human health. Broccoli flower crowns have been known to be rich in GLS. ARS scientists found that broccoli microgreens, 10-14 day old seedlings, contained four-fold greater total GLS content than that in mature broccoli leaves and broccoli crowns. In addition, preharvest calcium chloride applications significantly increased total GLS levels, while postharvest UV-B light exposure further boosted GLS levels in microgreens. Furthermore, preharvest calcium spray resulted in improved overall visual quality and longer storage life. This research provides valuable information to consumers on nutritive value of broccoli microgreens and provides the microgreen industry a protocol to improve broccoli microgreen nutritional quality.
Impacts
(N/A)
Publications
- Lu, Y., Dong, W., Yang, T., Luo, Y., Wang, Q., Chen, P. 2017. Effect of preharvest CaCl2 spray and postharvest UV-B radiation on storage quality of broccoli microgreens, a richer source of glucosinolates. Journal of Food Composition and Analysis. 67(1):55-62.
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Progress 10/01/16 to 09/30/17
Outputs
Progress Report Objectives (from AD-416): The overall goal of this project is to identify effective treatments that lead to improved product quality and nutritional value, and to identify the associated genetic elements responsible for fruit ripening and stress responses. Specific objectives are listed as follows: Objective 1: Evaluate and characterize changes in fruit ripening, postharvest nutritional and sensory quality parameters of strawberries due to pre- and post- harvest treatments with selected compounds, UV and calcium. Sub-objective 1.A. Identify effective treatment strategies that delay fruit ripening, improve postharvest nutritional and sensory quality parameters, and extend shelf-life. Sub-objective 1.B. Apply selected effective treatments to commercially harvested varieties of strawberries from different geographical regions, and validate efficacy and applicability of treatment(s) for industry. Objective 2: Identify key genes and signaling pathways regulating fruit ripening and biosynthesis of sugars, acids, volatile compounds and phenolics in response to effective treatments. Sub-objective 2.A. Conduct bioinformatic analyses of global gene expression profiles and correlate results with those obtained for physiological, metabolomic and sensory evaluations and identify candidate genes and signaling pathways that regulate the nutritional and sensory quality parameters. Sub-objective 2.B. Produce transgenic plants/fruits with the increased or reduced expression of selected candidate genes. Determine whether the up- and down- regulation of a single gene may mimic the improved quality traits that were observed in wild-type fruits following treatments. Approach (from AD-416): Locally grown strawberry fruit will be subjected to pre- and postharvest treatments with selective compounds, ultraviolet irradiation and calcium. Selective compounds are synthesized organic compounds, for example, the derivatives of benzoate, which have shown effect on fruit ripening and color. Fruit quality traits including firmness, soluble solid content, total titrable acid content, color and decay, as well as sensory parameters, such as taste, flavor and appearance, will be evaluated. Treatments that enhance nutritional and sensory quality will be further tested on diverse strawberry varieties produced by commercial strawberry growers throughout the United States. The metabolome profiles of targeted fruit phenolics and volatile compounds correlated to nutrition and flavor/ aroma in selected treatments will be analyzed by HPLC and GC-MS to determine which metabolites and pathways are altered. Global gene expression profiles in treated fruit will be analyzed by RNA sequence and bioinformatics analysis. The analyses will focus on genes involved in oxidative signaling, calcium signaling, and ABA signaling, as well as on the phenylpropanoid pathways and genes affecting biosynthesis of sugars, acids, volatile compounds. Stable or transient transformation with silencing or over-expression gene constructs driven by constitutive or fruit-specific promoters will be used to assess the function of specific genes in various aspects of fruit physiology and metabolism, including ripening, sensory parameters, responses to stresses, and accumulation and/ or retention of health-beneficial secondary metabolites from the phenylpropanoid pathway. Quality traits including flavor, color, firmness, stress tolerance, and phytonutrient content will be analyzed in the transgenic lines. This report covers year 1 of a 4-year project aimed at improvement of fresh produce quality, including appearance, texture, flavor, and nutrition. Objective 1 is to evaluate and characterize changes in fruit ripening, post-harvest nutritional and sensory quality traits, and shelf- life of strawberries due to pre- and post-harvest treatments with selected compounds, UV and calcium. Objective 2 focuses on identification of key genes and/or signaling pathways associated with regulating fruit ripening, nutritional and sensory quality traits in response to effective treatments. Strawberry is a non-climateric fruit, and the fruit ripening process is not clear. Thus, availability of effective postharvest storage management practices for strawberry are limited. To better understand the fruit development and ripening of strawberry, several novel chemical compounds (derivatives of benzoate) were tested on harvested fruit. These compounds displayed either stimulatory or delayed effects on fruit development and ripening. The effects of these chemicals on gene expression are being studied using RNA Sequence and RT-qPCR so as to identify the key genes affecting strawberry fruit ripening and quality. In addition to the effects of exogenously applied compounds on regulation of strawberry fruit ripening, fruit ripening and quality are affected by environmental conditions such as light, UV in particular. Preharvest UV treatment was done for six strawberry cultivars grown in low tunnels covered with three plastic films which can differentially block the UV transmittance. The three films are Clear TIII film (standard clear, STD), TIII TES/IR film (TES), and TempCool� film (TEM). TEM blocked 40% UV transmittance and TES lowered UV by 5%. The results indicated that strawberry genotype as well as the light composition during plant growth affected fruit quality and shelf life. Film type contributed dominantly for fruit weight loss. Films that block different levels of UV had no significant effect on total anthocyanin content or total phenolic content levels but significantly affected fruit color, total soluble solids and shelf life. For example, Monterey, Portola and Sweet Ann fruits had longer shelf-life under TEM, whereas Albion, San Andrea and Seascape lasted longer under TES. Thus plastic film selection requires consideration of plant genotype differences. In addition, harvested strawberry fruit were treated in the lab with UV-B light for different durations. The preliminary results showed that one time treatment was better than multiple treatments for fruit appearance and shelf life. Detailed analysis of metabolites and other parameters will be performed to determine the optimal treatment protocol. Broccoli microgreens have been reported to contain abundant glucosinolates (GLS), especially glucoraphanin (GLR) and glucoerucin (GLE) , which are associated with many health benefits. To boost the content of GLS in broccoli microgreens, the broccoli seedlings were treated with calcium chloride during the growth period, and with UV-B after harvest. Total aliphatic GLS levels increased significantly after 10 mM CaCl2 treatment, while postharvest UV-B radiation showed a minor effect on GLS contents. In addition, the synergistic study showed that 10 mM CaCl2 spray with UV-B treatments remarkably increased GLE and total aliphatic GLS contents in broccoli microgreens. The greatest proportion of variation for GLE, GLR, and total aliphatic GLS was attributed to calcium chloride. Thus, the enhancement of microgreen stress tolerance and defense by calcium chloride application could be the main factor for the increase in GLS levels. Peharvest CaCl2 and postharvest UVB have positive influence on maintaining the health-beneficial compounds and extending the shelf life of broccoli microgreens. Accomplishments 01 Determination that the activity of a key enzyme in strawberry involved in fruit anthocyanin biosynthesis is regulated by calcium. Anthocyanins are beneficial to human health. A key enzyme increases the accumulation of anthocyanins in strawberry, however, the activity of this enzyme is inhibited by other compounds in the biosynthetic pathway responsible for anthocyanin production. ARS scientists in Beltsville, Maryland, found that calcium, together with a calcium binding protein, significantly reduced this inhibition. These results provide new fundamental information on regulation of the anthocyanin biosynthetic pathway and are of immediate benefit to researchers working to enhance fruit anthocyanin content. The results will ultimately benefit consumers with commodities that have improved fruit quality and nutritive value. 02 An enzyme for health promoting compounds in a wild eggplant has higher activity than its counterpart in cultivated eggplant. Eggplant produces a variety of phenolic compounds beneficial to human health, however, little is known regarding regulation of the biosynthetic pathway that produces these compounds. ARS scientists at Beltsville, Maryland, identified an enzyme designated as SrSHT in eggplant and one of its wild relatives that is believed to be important in the production of these compounds. Heat-shock/drought treatments stimulated the expression of this enzyme in both leaves and fruits, indicating its involvement in plant stress responses that stimulate production of phenolics. These results were exaggerated in wild eggplant. These results will benefit plant breeders who can breed genes from exotic crop relatives into new cultivars to develop phenolic acid rich fruit for eggplant and other solanaceous crops with improved nutritive value. 03 Genes involved in drought and heat stresses response in strawberry (Fragaria vesca) identified. Strawberry plants are highly susceptible to environmental stress and stress resulting from pathogen attack. ARS scientists teamed up with scientists at the University of Tennessee and identified 50 genes from the woodland strawberry, a relative of the cultivated strawberry. Different genes affected developmental stages of various strawberry tissues and others were important for leaf development and for fruit development. Some genes were more active in response to environmental and biological stress. These results will be used to develop strawberry varieties with improved quality and resistance to stress caused by environmental extremes and pathogens.
Impacts
(N/A)
Publications
- Peng, H., Yang, T., Whitaker, B.D., Shangguan, L. 2016. Calcium/calmodulin alleviates substrate inhibition in a strawberry UDP-glucosyltransferase involved in fruit anthocyanin biosynthesis. Biomed Central (BMC) Plant Biology. 16:197. doi:10.1186/s12870-016-0888-z.
- Peng, H., Yang, T., Whitaker, B.D., Trouth, F.J., Shangguan, L., Dong, W., Jurick II, W.M. 2016. Characterization of spermidine hydroxycinnamoyl transferases from eggplant (Solanum melongena L.) and its wild relative Solanum richardii Dunal. Horticulture Research. 3:16062. doi: 10.1038/ hortres.2016.62.
- Lu, Y., Huang, L., Yang, T., Lv, F., Lu, Z. 2017. Optimization of a cryoprotective medium to increase the viability of freeze-dried Streptococcus thermophilus by response surface methodology. LWT - Food Science and Technology. 80:92-97. doi: 10.1016/j.lwt.2017.01.044.
- Wang, X., Chen, X., Yang, T., Cheng, Z., Cheng, Q. 2017. Genomic identification of bZIP family genes involved in drought and heat stresses in strawberry (Fragaria vesca). International Journal of Genomics. Available:
- Yan, S., Liu, H., Yang, T., Luo, Y., Chen, P. 2017. Dual effectiveness of ascorbic acid and ethanol combined treatment to inhibit browning and inactivate pathogens on fresh-cut apples. LWT - Food Science and Technology. 80:311-320.
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Progress 10/01/15 to 09/30/16
Outputs
Progress Report Objectives (from AD-416): The overall goal of this project is to identify effective treatments that lead to improved product quality and nutritional value, and to identify the associated genetic elements responsible for fruit ripening and stress responses. Specific objectives are listed as follows: Objective 1: Evaluate and characterize changes in fruit ripening, postharvest nutritional and sensory quality parameters of strawberries due to pre- and post- harvest treatments with selected compounds, UV and calcium. Sub-objective 1.A. Identify effective treatment strategies that delay fruit ripening, improve postharvest nutritional and sensory quality parameters, and extend shelf-life. Sub-objective 1.B. Apply selected effective treatments to commercially harvested varieties of strawberries from different geographical regions, and validate efficacy and applicability of treatment(s) for industry. Objective 2: Identify key genes and signaling pathways regulating fruit ripening and biosynthesis of sugars, acids, volatile compounds and phenolics in response to effective treatments. Sub-objective 2.A. Conduct bioinformatic analyses of global gene expression profiles and correlate results with those obtained for physiological, metabolomic and sensory evaluations and identify candidate genes and signaling pathways that regulate the nutritional and sensory quality parameters. Sub-objective 2.B. Produce transgenic plants/fruits with the increased or reduced expression of selected candidate genes. Determine whether the up- and down- regulation of a single gene may mimic the improved quality traits that were observed in wild-type fruits following treatments. Approach (from AD-416): Locally grown strawberry fruit will be subjected to pre- and postharvest treatments with selective compounds, ultraviolet irradiation and calcium. Selective compounds are synthesized organic compounds, for example, the derivatives of benzoate, which have shown effect on fruit ripening and color. Fruit quality traits including firmness, soluble solid content, total titrable acid content, color and decay, as well as sensory parameters, such as taste, flavor and appearance, will be evaluated. Treatments that enhance nutritional and sensory quality will be further tested on diverse strawberry varieties produced by commercial strawberry growers throughout the United States. The metabolome profiles of targeted fruit phenolics and volatile compounds correlated to nutrition and flavor/ aroma in selected treatments will be analyzed by HPLC and GC-MS to determine which metabolites and pathways are altered. Global gene expression profiles in treated fruit will be analyzed by RNA sequence and bioinformatics analysis. The analyses will focus on genes involved in oxidative signaling, calcium signaling, and ABA signaling, as well as on the phenylpropanoid pathways and genes affecting biosynthesis of sugars, acids, volatile compounds. Stable or transient transformation with silencing or over-expression gene constructs driven by constitutive or fruit-specific promoters will be used to assess the function of specific genes in various aspects of fruit physiology and metabolism, including ripening, sensory parameters, responses to stresses, and accumulation and/ or retention of health-beneficial secondary metabolites from the phenylpropanoid pathway. Quality traits including flavor, color, firmness, stress tolerance, and phytonutrient content will be analyzed in the transgenic lines. This report is for this new project which began June 2016, and continues research from 8042-43000-012-00D, "Genetic and Biochemical Mechanisms Determing Fresh Produce Quality and Storage Life." As this new project just began, there is no significant progress to report in FY16. Please see the report for bridging project 8042-43000-013-00D for more information.
Impacts
(N/A)
Publications
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