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

在有性繁殖周期后，从树冠上再生新的分蘖的能力是多年生束草的标志。相比之下，整个植物在一个有性繁殖周期后衰老，下一代是从一年生牧草的种子中建立起来的。由于种植一年生草本植物，如小麦、大麦、燕麦、水稻和玉米，每个季节都需要耕作土壤，这对环境有许多不利影响，包括向大气中释放吸热气体，因此在经济上有意义的应用中，最好用多年生谷物来取代一年生谷物。基于这一原理，本项目的目标是发现与小麦密切相关的高大冰草(Lophopyrum Arglatum)的多年生生长控制基因，并可用于创造小麦-冰草杂交植株。为了使这项研究成为可能，将对高大的冰草基因组进行测序。然后，将高大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，以确定控制多年生生长的基因。最后，将分析每个高大冰草染色体已分别整合到小麦基因组中的遗传库中的基因表达，以确定在高大冰草多年生生长中发挥核心作用的基因。所有项目成果将通过各种网站和长期储存库免费向公众开放。在这个项目中开发的知识和材料将在未来用于分离这些基因，并将它们应用于多年生小麦和其他谷物的育种，以减少农业对气候的影响。有性后循环再生(PSCR)是多年生冰草的多果生活史(PLH)的发育标志，这些冰草具有丛生或密集丛生/丛生生长习性。小麦缺乏PSCR，这是一种具有单果生活史(MLH)的一年生小麦。本项目的目标是通过分析杂交六倍体(2n=42)面包小麦品种的八倍体两倍体的基因表达来发现多年生小麦生长的关键基因。中国春(CS)×二倍体(2n=14)长穗麦和小麦。将每条长穗乳杆菌染色体分别添加到CS基因组中，并将每条长穗乳杆菌染色体分别替换其CS同源物。八倍体两倍体中的细长乳杆菌基因组将被测序，并对基因进行注释。基因表达将与CS在包括PSCR在内的一个生殖周期内进行比较。我们将对二体替换系中的基因表达进行比较，以确定在长穗莲子基因组中对PSCR表达起关键作用的基因。从以前的NSF资助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。由于一年生牧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多年生小麦、燕麦和其他谷物将具有实际意义。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.