Collaborative Research: Mechanisms of pollen-specific phospholipases in maize haploid production

有性繁殖将来自两个亲本的遗传物质混合在一起，这是自然选择的驱动力，也是植物育种改良的基础。然而，确保遗传信息从每个亲本传递到下一代的细胞和分子机制在很大程度上是未知的。该项目研究了切割磷脂的特定酶如何影响玉米种子生产中的精子基因组转移，磷脂是细胞膜的组成部分，如精子和卵细胞的细胞膜。这些酶的遗传缺陷导致一些胚胎没有精子基因组，产生仅具有来自卵子的遗传信息的母体单倍体。本研究将探讨这些酶如何影响膜脂的变化，以及脂质的变化如何导致单倍体的形成。因此，该项目的研究结果将推进对精子基因组稳定性和单倍体种子生产的基本机械理解，并可能应用于作物改良，例如单倍体诱导技术，以提高作物育种和食品，饲料，燃料和工业原料的生产。该项目将通过为学生和博士后研究人员提供培训机会，并作为扩大代表性不足群体参与研究的平台，对科学、教育和社会产生更广泛的影响。包括各种玉米品系在内的研究材料将分发给社区，研究结果和大型数据集将通过讲座和研讨会、课堂教学、国家和国际会议以及通过在同行评议期刊上及时发表来传播，以加强科学和教育。本项目的目标是阐明两种花粉特异性磷脂酶，pPLAIIφ和PLD 3，与谷类作物的精子基因组传递和单倍体种子产生有关。该研究验证了以下假设：pPLAIIφ和PLD 3活性的丧失扰乱了受精过程中的脂质稳态、膜结构和精卵膜融合，导致单倍体诱导和种子产量下降。支持性目的是：1）确定pPLAIIφ和PLD 3催化活性在单倍体和种子生产中的作用，2）表征磷脂酶对花粉和精子膜脂质稳态的影响，和3）测量脂质动力学和对精卵融合的影响。研究结果将促进对精子基因组稳定性和有性生殖的理解，并有可能确定适用于增强作物改良单倍体诱导的化学和分子修饰剂。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Sexual reproduction mixes the genetic materials from two parents, which is the driving force for natural selections and a basis for plant breeding improvements. However, the cellular and molecular mechanisms that ensure the transfer of the genetic information from each parent to the next generation are largely unknown. This project addresses how specific enzymes that cleave phospholipids, which are building blocks of cell membranes, such as those of sperm and egg cells, affect the sperm genome transfer in maize seed production. Genetic defects in those enzymes lead to some embryos without the sperm genome, producing maternal haploids with genetic information only from the egg. This study will investigate how those enzymes affect membrane lipid changes and how the lipid changes lead to haploid formation. Thus, findings from this project will advance the fundamental, mechanistic understanding of sperm genome stability and haploid seed production with potential applications to crop improvement, such as haploid induction technology to enhance crop breeding and production for food, feed, fuel, and industrial feedstocks. This project will have additional broader impacts on science, education, and society by providing opportunities for training of students and postdoctoral researchers and serving as a platform to broaden participation of underrepresented groups in research. The research materials, including various maize lines, will be distributed to community and the results and large datasets will be disseminated to enhance science and education through lectures and seminars, in classroom teaching, at national and international meetings, and through timely publications in peer-reviewed journals.The goal of this project is to elucidate how two pollen-specific phospholipases, pPLAIIφ and PLD3, are involved in sperm genome transmission and haploid seed production in cereal crops. The research tests the hypotheses that loss of the pPLAIIφ and PLD3 activities perturbs lipid homeostasis, membrane structures, and sperm-egg membrane fusion during fertilization, leading to haploid induction and decreased seed production. The supporting objectives are to: 1) determine the role of pPLAIIφ and PLD3 catalytic activities in haploid and seed production, 2) characterize the effect of the phospholipases on pollen and sperm membrane lipid homeostasis, and 3) measure lipid dynamics and effects on sperm-egg fusion. The results will advance the understanding of sperm genome stability and sexual reproduction and have the potential to identify chemical and molecular modifiers applicable to enhance haploid induction for crop improvement.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.