MOLECULAR BIOLOGY AND GENETICS BEHIND FRUIT TREE DEVELOPMENT AND PHYSIOLOGY

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1013242
• Project Start Date: Sep 1, 2017
• Project End Date: Aug 31, 2022
• Program Code: [(N/A)]- (N/A)

Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824

Performing Department
Horticulture

Non Technical Summary
The deciduous tree fruit industry makes up a significant part of Michigan's agricultural revenue. In 2016, Michigan was the third largest Apple producing state, the top sour cherry producer, and the fourth largest sweet cherry producer in the country (Michigan Ag Council, 2017; Cherry Marketing Institute, 2016). Over 800 farms in our state produce ~966 million pounds of apples each year (a value of $700-900 million), and Michigan cherry farmers grew 237.5 million pounds of sour cherries last year (valued at $53.4 million) (Michigan Ag Council, 2017; Cherry Marketing Institute, 2016). But despite past and current success of the Michigan tree fruit industries, their continued survival depends on their ability to produce more fruit with fewer resources, constant and new pest and pathogen challenges, and to overcome the now frequent erratic weather patterns due to global climate change. One of these challenges was exemplified during the infamous 2012 Spring frosts that left Michigan sour cherry growers with less than 10% of the prior year's production and opened the industry up to competition from producers outside the United States (Cherry Marketing Institute, 2016). This year, 2017, we're also unfortunately on track to have another significant cherry and apple crop loss due to post-bloom freeze events in early May.In order to maintain, if not increase the success of Michigan tree fruit industries, new strategies are needed to make tree fruit production more sustainable in this state. This research program focuses on understanding aspects of plant genetics, physiology, and development that could greatly benefit Michigan tree fruit growers. While this topic may seem broad, the specific research goals for the next five years focus on two areas: 1) generating a greater understanding of the genetics, physiology, and molecular biology that regulates tree architecture, and 2) generating a greater understanding of the biology behind bloom time in fruit trees. The goal of the first project is to find novel ways to breed fruit trees with "out-of-the-box" ideal architectures, or growth habits. This includes growth habits that require less labor and training for high-density plantings. High-density orchards can enable more fruit production per acre, reduced spray volume and costs, and mechanization. The second research focus, understanding the biology of bloom time, is aimed at breeding trees that are more resistant to early spring frost events because they bloom later in the season.The goal of this research program is to generate knowledge and products (such as molecular markers, germplasm for breeding, elite cultivars, and/or cultural practices) that will benefit fruit tree breeding and tree fruit production in Michigan and throughout the United States. This work aligns well with the AgBio Research's mission of promoting leading innovation in food, and it may have an impact on maintaining natural resources by reducing the impact of tree agriculture on the environment. The research also covers USDA Knowledge Areas 201 (Plant genome, Genetics, and Genetic Mechanism) and 202 (Basic Plant Biology) under Topic II, Plants and their systems. In the long run this research may contribute to Knowledge Areas 202 (Plant Genetic Resources) and 204 (Plant Product Quality and Utility, pre-harvest).

Animal Health Component

(N/A)

Research Effort Categories

Basic

50%

Applied

(N/A)

Developmental

50%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
201	0699	1020	10%
201	0699	1040	10%
201	0699	1050	10%
202	1110	1081	10%
202	1112	1081	10%
202	1116	1081	10%
206	0699	1050	10%
206	0699	1040	10%
206	0699	1080	10%
206	0699	1020	10%

Knowledge Area
206 - Basic Plant Biology; 202 - Plant Genetic Resources; 201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1110 - Apple; 1112 - Cherry; 1116 - Plum; 0699 - Trees, forests, and forest products, general;

Field Of Science
1040 - Molecular biology; 1081 - Breeding; 1080 - Genetics; 1020 - Physiology; 1050 - Developmental biology;

Keywords

apple

cherry

plant architecture

bloom time

flower development

dormancy

plant development

tree physiology

tree genetics

Goals / Objectives
The major objectiveof this research program is to findsolutions to challenges that face Michigan tree fruit growers through a basic research on the molecular biology and genetics of plant development and physiology. This includesgeneratingknowledge and products (such as molecular markers, germplasm for breeding, elite cultivars, and/or cultural practices) that will benefit fruit tree breeding and tree fruit production in Michigan and throughout the United States.One specific long-term goal of this work is to develop apple and sweet and sour cherry cultivars with growth habits that are more easily amenable (and require less labor) to grow in high-density plantings. This could increase profitability by decreasing the amount of resources needed for production and at the same time reduce the environmental impacts on the land as sprays would cover less acreage. Another specific long-term goal is the development of late-blooming cherry cultivars. These would be less susceptible to crop losses from early spring frosts. Lastly, an additional goal is the generation of molecular markers for breeding beneficial traits in apple, sweet cherry, sour cherry, and peach breeding purposes, including ones for disease resistance.Specific 5-Year Objectives1) Decipher molecular functions of genes associated with lateral shoot orientations in plants, including but not limited to TAC1, LAZY1, and WEEP.2) Complete the generation of plum, apple, and cherry trees with modified architectures due to manipulation by genetic engineering of TAC1, LAZY1, and GID1c genes and initiate field trials to test their utility3) Perform genomic sequencing experiments and analyses for the purpose of developing a highly accurate molecular marker for bloom time in existing cherry populations.4) Determine tissue-specific gene expression profiles for phenological stages of sour cherry flower bud development to identify target genes for the breeding/engineering late flowering cherry cultivars, and initiate genetic engineering tests of their utilityThis work aligns well with the AgBio Research's mission of promoting leading innovation in food, and it may have an impact on maintaining natural resources by reducing the impact of tree agriculture on the environment. The research also covers USDA Knowledge Areas 201 (Plant genome, Genetics, and Genetic Mechanism) and 202 (Basic Plant Biology) under Topic II, Plants and their systems. In the long run this research may contribute to Knowledge Areas 202 (Plant Genetic Resources) and 204 (Plant Product Quality and Utility, pre-harvest).

Project Methods
Methods for Objective 1:A multitude of molecular biology experiments will be performed to gain further insight into the molecular functions of plant architecture genes TAC1, LAZY1, and WEEP. These methods include but are not limited to the following: Determining protein-protein interactions using a combination of yeast-two-hybrid assays and Immunoprecipitation (pull-down) assays, performing pull-downs followed by chromatography, and performing bi-molecular fluorescent complementation assays. The ability of TAC1, LAZY1, WEEP, and related proteins to bind nucleic acid will be tested using gel-shift assays. If proteins bind to DNA, a Chromatin Immunoprecipitation (ChIP) assay will be performed followed by quantitative real-time PCR (qPCR) and/or genomic sequencing to determine DNA targets. Identifying tissue-specific gene expression and protein localization patterns will be determined using combinations of qPCR and RNA-sequencing from dissected tissues, reporter gene expression in arabidopsis, and immunohistology. Changes in gene expression or protein localization in response to environmental triggers (such as alterations in light and orientation) may also be investigated if appropriate. Further, subcellular localization of the proteins will be determined using fluorescently tagged proteins or immunohistology. Tissue-specific phytohormone levels in architecture mutants (model plants and fruit trees with non-standard growth habits) may also be assessed. Lastly, if additional genetic interactions are hypothesized, arabidopsis with mutations in multiple genes will be generated to look for epistatic interactions. All facilities and equipment for these experiments are available in the Hollender lab or the MSU Research Technology and Support Facility (RTSF) and the MSU Center for Advanced Microscopy.Methods for Objective 2:Buds from existing transgenic plum trees that have modified expression of TAC1, LAZY1 will be grafted on to standard plum rootstocks, planted in the field and their growth habit and utility for production systems will be evaluated when grown under training systems including espalier-type trellis systems, the UFO system, and/or a central leader system. In addition, apple, sour cherry, and sweet cherry trees with modified expression of TAC1, LAZY1, and GID1c will be generated using genetic engineering. After ~ 1 to 2 years of greenhouse growth they will be transplanted into a field for evaluations with and without trellis training. The MSU Clarksville Research Center will be used for field plantings, permitting APHIS containment requirements can be met at that location. Additional or alternative planting sites may include the Southwest Michigan Research and Extension Center and/or the MSU Horticulture Teaching and Research Center.Methods for Objective 3:Amy Iezzoni's sour cherry breeding populations at Clarksville that segregate for bloom time will used develop genetic markers (and possibly identify genes) for bloom time using the p-nome mapping approach (described in Dardick et al., 2013). DNA will be extracted from leaves from every tree of the populations that segregate for bloom time and pools of DNA for late and early flowering trees from each population will be sequenced using Illumina next-generation sequencing. The CLC Genomics Workbench software program will be used to identify polymorphisms (such as SNPs) between each pool and known genome sequences. The polymorphisms from each pool will then be cross-referenced and candidate genes and/or polymorphisms that may be associated with either late or early flowering will be identified. Genetic markers for bloom time in sour cherry will be developed from this data. The data may also result in novel candidate genes to target for breeding late flowering into transformable species via genetic engineering. DNA extractions and sequence analysis will be performed within the Hollender lab. DNA sequencing will likely be performed at the MSU Research Technology Support Facility.Methods for Objective 4:Whole flower buds and/or dissected bud tissues will be isolated from sour cherry trees from Dr. Amy Iezzoni's breeding populations at Clarksville Research Center. Tissues will be collected throughout bud development. Corresponding phenological stages will be determined through additional dissection, sectioning, growing degree days (GDD), and/or comparison with existing work. Dr. Todd Einhorn's expertise in cherry bud phenology will aid in this part of the project. RNA will be extracted from the tissues and sent for Illumina sequencing at the MSU Research Technology Support Facility. Analysis of the sequencing data will be performed using the CLC Genomics Workbench software. Genes with differential expression between buds from earlier and later flowering trees at the same time point and between the different stages of development will be determined. This will be done to identify single genes or pathways of genes whose expression is correlated to stages of bud dormancy and bud break. These genes will then become targets for developing later flowering sour and sweet cherry trees and their expression will be altered in cherry trees via genetic engineering of cultivars in tissue culture at the MSU Plant Biotechnology Resource and Outreach Center (PBROC).

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:The target audience reached during this reporting period includedmembers of theplantscience research community andtree fruit industry stakeholders. Changes/Problems:Some progress towards all four of the 5-year objectives was made during this reporting preriod. However, the COVID-19 pandemic greatly impacted this research project. There were several months when research was completely halted. After research started upthis past summer, the rate at which our planned experiements could be completed was greatly reduced and still is. On average, the reserach under this project associated with plant architecture has been delayed by about 6months, and the generation and phenotyping of transgenic trees is now delayed by one year. An upcoming funded collaboration between my resarch lab and the company Pairwise was also put on hold because of the MSU research restrictions that went into place in March. Planned research dissemination activies were also canceled due to COVID-19. This included a posterpresentation by my post-doctoral resarcherat the American Society for Plant Biologist annual conference (Plant Biolology 2020) as well as an invited talk I was to give at the Auxin 2020 meeting. In addition, the effect of the COVID-19 research shut-down and slow-down will sadly reduce the number of publications that the post-doctoral researcher will be able toauthor prior to the end of his time inmy lab and his faculty job search. Lastly, the deleterious spring frosts that occured in Michigan in May 2020 killed our entire peach crop. As a result, we were unable to collect our first year of data on fruit quality from our peach training studies. What opportunities for training and professional development has the project provided?The post-doctoral resarch and the two graduate students working on this project trainedof two undergraduate students in a one-on-one capacity. The undergraduate students were trained in both research and data analysis methods. In addition, the PI was part of a science communication fellowship program within Michigan State University to learn how to best communicate research to the public via different media outlets. How have the results been disseminated to communities of interest?The purpose and accomplishments of our research has been communicated to members of the plant science community and to stakeholders through oral and poster presentations (as described in previous sections). In addition, our research was disseminted via informal presentations within Michigan State University, including joint lab meetings with other MSU researchers. What do you plan to do during the next reporting period to accomplish the goals?During this next reporting period, extensive molecular, genetic, and genomic experiments will be performed in order to achieve the 5-year objectives. In addition, further tree training studies will be conducted in the field and the newly acquired apple germplasm will be evaluated and further experiments will be developed.

Impacts
What was accomplished under these goals? Throughout this reporting periodmy research lab perfromed molecular, genetic, and genomic researchthat will enable accomplishing the following major goals: 1) Establishing an increased understanding of how fruit trees regulate their branch angles, 2) Establishing a greater understanding of how fruit trees regulate their bloom time, and 3) Establishing an annotated sequenced genome for the commercial tart cherry varietyMontmorency. Research on the first goal may lead to the development of a variety of fruit trees that easily ammenable for high-density plantings. Outcomes from the second goal may lead to the development of new strategies to delay bloom time for the purpose of avoiding crop loss from severe spring freezes. Lastly, the third goal (the development of a sequenced tart cherry genome) will enhanceresearch into tart cherry biology for the purposes of aiding production for US growers. Specific accomplisments for each of the 5-year objectives are described below: Objective 1) Decipher molecular functions of genes associated with lateral shoot orientations in plants, including but not limited toTAC1,LAZY1, andWEEP. Accomplisments Tissues for gene expressions studies for all three genes were collected from peach trees, tobacco, tomato, and arabidopsis Expression analyses of these genes for the collected tissues was initiated Tissues from peach trees with and without a mutation in the WEEP gene were collected for future horomone analyses Analysis of proteins which may directly regulate the expression of the genes listed above was inititated. This includes the documentation of phenotypes of arabidopsis plants with mutations in the candidate regulators as well as the generation of arabidopsis plants with mutations in those genes alongside mutations in TAC1 and LAZY1 The response of weeping and non-weeping peach tree shoots to application of the plant hormone auxin was assessed The generation of transgenic tobacco plants that have mutations in WEEP as well as transgenic tobacco that overexpresses WEEP was initated, along with negative controlsand several promising plant linesare currently being studied Objective 2) Complete the generation of plum, apple, and cherry trees with modified architectures due to manipulation by genetic engineering ofTAC1,LAZY1, andGID1cgenes and initiate field trials to test their utility Accomplishments Cherry and apple cultivars are being maintained in tissue culture Seeds and plants for culturing additional cherry varieties were acquired Troubleshooting for apple transformation is underway A multi-year field trial containing transgenic plums with manipulated expression of WEEP, LAZY1, TAC1, and GID1 is underway at the Clarksville Research Center. This includes tree training studies and studies of their natural growth habits.The first extensive pruning and trainings were performed this year. Objective 3) Perform genomic sequencing experiments and analyses for the purpose of developing a highly accurate molecular marker for bloom time in existing cherry populations. Accomplishments Genomic DNA from montmorency tart cherry trees, as well as additional wild cherry species has been sequenced RNA from multiple types of tissues fromtart cherry and tart cherry ancestors has been sequenced Genome assembly and annotation for Montmorency tart cherry has been initated Past genomic sequencing data from early and late blooming tart cherry sibling trees was reanalyed for the purposed of identifying candidate genes for bloom time regulation. Objective 4) Determine tissue-specific gene expression profiles for phenological stages of sour cherry flower bud development to identify target genes for the breeding/engineering late flowering cherry cultivars, and initiate genetic engineering tests of their utility Accomplishments Tissues have been collected from tart cherry trees with early and late bloom times for future sequencing that will help identify candidate genes associated with bloom time Comprehensive morphological data about the development of early and late blooming tart cherries was generated through the documentation adn analysis of the physical changes of developing flowers in early- and late-blooming trees over the course of a year. This anlysis will help narrow the developmental time points that we will use for upcoming gene expression studies. ?

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Hollender CA, Hill JL, Waite J, Dardick C. (2020) Opposing influences of TAC1 and LAZY1 on Lateral Shoot orientation in Arabidopsis. Scientific Reports 10, 6051 https://doi.org/10.1038/s41598-020-62962-4
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Hollender and van Nocker. (2019) The MSU Apple Variety Reference Collection: A New Resource for Michigan Apple Production and Genetics Research. Great Lakes Fruit, Vegetable & Farm Market Expo. Grand Rapids, MI.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Goeckeritz, Azmi, Iezzoni, and Hollender. (2019) Untangling the mechanism of bloom time differences in a population of tart cherry. Great Lakes Fruit, Vegetable & Farm Market Expo. Grand Rapids, MI.

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:The target audiece reached during this reporting period included members of the plant science community as well astree fruit industry stakeholders. The members of the scienctific communitythat were reached includeattendees of the follow meetings or insitutes, where this research was presented: 1. FASEB Mechanisms in Plant Development Conference, where two members of my lab presented posters (Olean NY, July 2019), 2.The International Plant Growth Substance Associationmeeting, where I gave a research talk (Paris, France,June 2019);3.Researchers at the INRA Amelioration Génétique et Adaptation des Plantes Méditerranéennes et Tropicales (AGAP), Montpellier, France (where I gave a talk in July 2019), and 4. Cornell UniversitySchool of Integrative Plant Sciences Horticulture Seminar (where I gave a talk on October 1st, 2018). Tree fruit stakeholders were reached during a presentation of our field planting at the MSU Clarksville Research Center on August 14th, 2019. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided individualized research training for one post-doctoral researcher, two PhD students, and two undergraduate students. It has also provided each of these scientists with professional training related to presenting scientific results via research papers, posters, and/or oral presentations. How have the results been disseminated to communities of interest?These results were reported to both scientific and stakeholder communities (as described earlier) via scientific research presentations and a tour at the MSU Clarksville Reserach Center during a field day event that was open to the public and attended by stakeholders and community members. What do you plan to do during the next reporting period to accomplish the goals?During the course of the next reporting period, additional experiements and data collection related to the proposed objectives will be carried out.

Impacts
What was accomplished under these goals? The indended impact of this research is to findsolutions to the challenges faced by tree fruit growers. Solutions will emerger from the results of a basic research on the molecular biology and genetics of plant development and physiology. In this reporting period, there were several significant accomplishments that are moving the resarch program towards meeting all four of its objectives. The accomplishments inlcude furthering our knowledge related to the genes that regulate tree branch orientations and bloom time and generating tools and resources for future related research. Details are provided below. For Objective 1 (Decipher molecular functions of genes associated with lateral shoot orientations in plants, including but not limited toTAC1,LAZY1, andWEEP)this includes but is not limited to: A)The development of antibodies to determine what proteins interact with the TAC1, LAZY1, and WEEP proteins, B) The determination of where TAC1 and LAZY1 are expressed intobacco and tomato, C) The identification of possible genetic interactors for TAC1, LAZY1, and WEEP via the analysis of data from Yeast-One-Hybrid Experiments along with gene expression studies and the generation of plants with multiple achitecture gene mutations, For Objective 2 (Complete the generation of plum, apple, and cherry trees with modified architectures due to manipulation by genetic engineering ofTAC1,LAZY1, andGID1cgenes and initiate field trials to test their utility), this includes, but is not limited to:A) progress on the development of apple trees with modified expression of TAC1 and LAZY1,, including molecular cloning of essential constructs, bulking up of invitro apple cultures, and trouble shoot of plant transformation systems.B)the installation of a planting and subsuquent inititaion of a training trial for peach and plum trees with modified expression of TAC1, LAZY1, and GID1c For Objective 3 (Perform genomic sequencing experiments and analyses for the purpose of developing a highly accurate molecular marker for bloom time in existing cherry populations), this includes but is not limited to:A) The sequencing of genomic DNA from a variety of tart cherry and tart cherry progenitors for the purpose of developing an annotated tart cherry genome, B)The generation and analysis of RNAseq gene expression data from a variety of apple flower buds from trees with extremely early and extremely late bloom times. For objective 4 (Determine tissue-specific gene expression profiles for phenological stages of sour cherry flower bud development to identify target genes for the breeding/engineering late flowering cherry cultivars, and initiate genetic engineering tests of their utility), this includes but is not limited to: A) Performing a year longphenological study on flower development fora variety of apple and tart cherry germplasm that exhibits extreme differences in bloom time

Publications

• Type: Other Status: Published Year Published: 2019 Citation: Hill JL, Kohler A, Al-Haddad J, Telewski F, Hollender CA. Molecular Characterization of the role of WEEP in directing lateral organ orientation. Published abstract for poster Presented at FASEB Mechanisms of Plant Development Conference, Olean, NY.
• Type: Other Status: Published Year Published: 2019 Citation: Goeckeritz C, Azmi A, Iezzoni AF, Hollender CA. Untangling the mechanism of bloom time differences in a tart cherry (Prunus cerasus) population. Published abstract for poster and short talk presented at FASEB Mechanisms of Plant Development Conference, Olean, NY.
• Type: Other Status: Published Year Published: 2019 Citation: Hollender CA. Hormonal Control of Branch Orientation Relies on the Integration of Light and Gravity Signaling via TAC1, LAZY1, and WEEP. Published abstract for talk given at IPGSA 23rd International Conference on Plant Growth Substances. Paris, France.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:The target audience for this project during this reporting periodincludedmembers of the scientific community. I presented this work at the ASHS annual conference in August 2018 during an invited talk. At the same conference, both my graduate student Charity Goeckeritz and my post-doc Joseph Hill also presented posters related to this project.In addition, a summer student in my lab, Mallory St. Clair, presented a poster on research under thisproject at theMid-Michigan Symposium for Undergraduate Research Experiences (Mid-SURE) poster session in July 2018. Lastly, aspects of the work were published in two peer reviewed journal articles:Hollender et al(2018) Alteration ofTAC1expression in Prunus species leads to pleiotropic shoot phenotypes.Horticulture Research5:26 DOI 10.1038/s41438-018-0034-1 &Hollender et al.(2018) Loss of a highly conserved Sterile Alpha Motif domain gene (WEEP) results in pendulous branch growth in peach trees. DOI: 10.1073/pnas.1704515115 Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has led to the training of one post-doctoral resarcher, two graduate students, and two undergraduate students. Training was done via one-on-one interactions. How have the results been disseminated to communities of interest?This project and current results have been described in conversation to stakeholders in the tree fruit industry during visits to my resarch facility as well as dicussion at activities organized by extension educators. What do you plan to do during the next reporting period to accomplish the goals?Additional experiments andfield trials will be performed.

Impacts
What was accomplished under these goals? Progress for each objective is as follows Objective 1: The results of theexperiments performeddetermine the function of architecture genes have led to increased knowledge on the roles of these genes and an improved model of the regulation of plant form. Objective 2: Apple tissue culture and transfortmation was started for the TAC1 gene. Tissue cultures of multipleapple and cherry cultivars were achieved. These cultures will be used for future transformations. Existing transgenic plums with modified expression of architecture genes were planted at the MSU Clarksville Research Center and observational and field training studies have commenced. Objective 3: Genomic sequencing was performed for one population of early and late blooming sour cherries. Objective 4: Tissue was collected for performing gene expression analyses on cherry.

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: Hollender CA, Guseman J, Tabb A, Raines D, Srinivasan C, Dardick C. (2018) Alteration of TAC1 expression in Prunus species leads to pleiotropic shoot phenotypes. Horticulture Research 5:26 DOI 10.1038/s41438-018-0034-1
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Hollender CA , Pascal T , Tabb A , Hadiarto T, Srinivasan C , Wang W, Liu Z , Scorza R , Dardick C. (2018). Loss of a highly conserved Sterile Alpha Motif domain gene (WEEP) results in pendulous branch growth in peach trees. DOI: 10.1073/pnas.1704515115
• Type: Journal Articles Status: Accepted Year Published: 2019 Citation: Hill and Hollender (2019 - predicted) Branching Out: New Insights into the Genetic Regulation of Shoot Architecture in Trees. Current Opinions in Plant Biology - In Press
• Type: Other Status: Published Year Published: 2018 Citation: Hill J, Al-Haddad J, Telewski F, Hollender CA. (2018) Molecular Characterization of the Role of WEEP in Directing Branch Orientation in Peach Trees. American Society for Horticultural Science Annual Conference
• Type: Other Status: Published Year Published: 2018 Citation: Goeckeritz, C, Hill J, Sebolt A, Iezzoni A, Hollender CA*. (2018) Variation in Floral Bud Development between Early and Late Blooming Tart Cherries. American Society for Horticultural Science Annual Conference.

Progress 09/01/17 to 09/30/17

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?Over the next year, a considerable amount of effort will be put forth by multiple lab members to make progress on all four of the objectives. For objective 1, we will perform experiments to begin todetermine the tissue-specific expression profiles of the architecture genes TAC1, LAZY1, and WEEP (and possibly others). In addition, we will make progress on identifying proteins that interact with architecture proteins and on identifyingproteins that interact with thepromoters of these genes. For objective 2, tissue cultures ofadditional apple and cherry cultivars will prepared and DNA plamids designed to modify the expression of architecture genes will be generated. A field trial using transgenic plums that have modified architecture will also be initiated, APHIS permit permitting.For objectives3 and 4, a subset of genomic and/or transcriptomic sequencing will be performed for tissues from tart cherry treethat have diverse flowering times.

Impacts
What was accomplished under these goals? In the one month period being reported here, progress was made on both objecteives 1 and 2. As part of our lab's effort to decipher the functions of genes associated with lateral shoot orientations in plants (Objective 1), hormone profiles for two different shoot architecturemutants (tac1 and lazy1) were generated. This knowledge will help determine the physiological and molecular role these genes have in regulating shoot architecture. In relation ot objective 2, progress was madeon generating and maintaining apple and cherry tissue cultures. Additionally, an apple cultivar (gala) was transformed with a construct that should eliminate the funciton of the TAC1 gene. Lastly, in connection to objective 2, budwood from transgenic plums containing modified expression levels of the TAC1 and LAZY1 genes were grafted on to plum rootstock for use in a future field trial in Michigan.

Publications