RESEACH-PGR: Genomics of the Perennial/Annual Dichotomy in the Grass Tribe Triticeae

在有性繁殖周期后，从树冠上再生新分蘖的能力是多年生束草的标志。相反，整个植物在一个有性生殖周期后衰老，下一代是从一年生草的种子中建立的。由于一年生禾本科植物如小麦、大麦、燕麦、水稻和玉米的种植需要每个季节耕作土壤，这对环境具有许多不利影响，包括将吸热气体释放到大气中，因此在具有经济意义的应用中，希望用多年生形式代替一年生谷物。基于这一基本原理，本项目的目标是发现控制高冰草（Lophopyrum elongatum）多年生生长的基因，高冰草与小麦密切相关，可用于创造杂交小麦-冰草植物。为了使这项研究成为可能，高冰草基因组将被测序。然后将高冰草基因组中存在的基因的表达与小麦在一个生殖周期中的表达进行比较，以鉴定控制多年生生长的基因。最后，基因表达的遗传股票，其中每个高冰草染色体已被单独纳入小麦基因组将进行分析，以确定基因发挥核心作用，使高冰草多年生生长。所有项目成果都将通过各种网站和长期资料库免费公开获取。本项目所获得的知识和材料将在未来用于分离这些基因，并将其应用于小麦和其他谷物的多年生形式的育种中，以减少农业对气候的影响。有性周期后再生（PSCR）是多年生偃麦草属（Lophopyrum）中多果生活史（PLH）的发育标记（小麦族，禾本科），显示丛生或密集的丛生/丛生生长习性。PSCR是缺席小麦，一年生一次结实的生活史（MLH）。本项目的目标是通过分析来自杂交六倍体（2n=42）面包小麦cv的四倍体双倍体的基因表达来发现多年生生长的关键基因。中国春（CS）×二倍体（2n=14）L. elongatum和小麦。每个L.将长穗偃麦草染色体单独添加到CS基因组中，并且每个L. elongatum染色体被其CS同源物单独取代。洛杉矶将对存在于二倍体双倍体中的长体植物基因组进行测序，并对基因进行注释。将在一个生殖周期（包括PSCR）中与CS中的基因表达进行比较。将比较二体置换系中的基因表达以鉴定对L. elongatum基因组从先前的NSF支持中开发的材料将用于探索性研究，旨在扩大该项目的社会影响。由于一年生草的种植伴随着不良的生态后果，包括土壤中的碳固存不良和向大气中释放吸热气体，因此所开发的知识对于未来培育一年生小麦、燕麦、该奖项反映了NSF的法定使命，并被认为是值得通过评估使用基金会的知识优点和更广泛的影响审查标准。

The ability to regrow new tillers from the crown after a cycle of sexual reproduction is the hallmark of perennial bunchgrasses. In contrast, the entire plant senesces after a single sexual reproductive cycle and the next generation is established from seeds in annual grasses. Since the cultivation of annual grasses, such as wheat, barley, oats, rice, and maize, requires tilling of soil each season, which has numerous detrimental effects on the environment including release of heat-trapping gases into the atmosphere, it would be desirable to replace annual cereals with perennial forms in applications in which it makes economic sense. Based on this rationale, the goal of this project is to discover genes controlling the perennial growth in tall wheatgrass (Lophopyrum elongatum), which is closely related to wheat and can be used to create hybrid wheat-wheatgrass plants. To make this study possible, the tall wheatgrass genome will be sequenced. Expression of genes present in the genome of tall wheatgrass will then be compared with that of wheat during one reproductive cycle to identify genes controlling perennial growth. Finally, gene expression in genetic stocks where each tall wheatgrass chromosome has been individually incorporated into the wheat genome will be analyzed to identify genes playing the central role in bringing about perennial growth in tall wheatgrass. All project outcomes will be freely and publicly accessible through various websites and long term repositories. The knowledge and materials developed in this project will be used in the future to isolate these genes and to deploy them in breeding perennial forms of wheat and other cereals, in order to reduce the impact of agriculture on climate.Post-sexual cycle regrowth (PSCR) is a developmental marker for the polycarpic life history (PLH) in the perennial wheatgrasses of the genus Lophopyrum (tribe Triticeae, Poaceae) that show a caespitose or dense clumped/tufted growth habit. PSCR is absent from wheat, an annual with a monocarpic life history (MLH). The goal of this project is to discover key genes for perennial growth by analyzing gene expression in an octoploid amphiploid from the cross hexaploid (2n=42) bread wheat cv. Chinese Spring (CS) × diploid (2n=14) L. elongatum and in wheat. Each L. elongatum chromosome was individually added to the CS genome and each L. elongatum chromosome was individually substituted for its CS homoeologues. The L. elongatum genome present in the octoploid amphiploid will be sequenced and genes will be annotated. Gene expression will be compared with that in CS across one reproductive cycle including PSCR. Gene expression in the disomic substitution lines will be compared to identify genes with critical role for the expression of PSCR in the L. elongatum genome. Materials developed from prior NSF support will be used in exploratory research aiming at broadening the societal impact of this project. Since the cultivation of annual grasses is accompanied by undesirable ecological consequences, including poor carbon sequestration in soil and release of heat-trapping gases into the atmosphere, the developed knowledge will be practically important for future breeding of perennial forms of annual wheat, oats, and other cereals.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.