Genetic dissection of ovule and embryo abortion in heat-stressed pea

热应激豌豆胚珠和胚胎败育的遗传解析

• 批准号: 534229-2018
• 负责人: Bueckert, Rosalind
• 金额: $ 3.85万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=698515
• 关键词: Genetic; dissection; ovule; embryo; abortion

Pea plants and crops are sensitive to stress like heat and drought, and readily abort flowers and young pods, lowering yields. An ovule is a potential pea seed within a pod before it is fertilized by pollen. On successful pollination, each fertilized ovule contains a small embryo that develops into a seed. Flower and seed loss is likely because ovules are susceptible to heat damage. While pollination is known to be fussy about heat and high temperature days, we know far less about how ovules and young embryos fare in heat. This project looks at pea varieties and develops methods to measure heat stress on ovules hidden inside flowers. We are first using two traditional methods on tiny pods and their ovules, collected from plants four days after a flower is open. Here we can view ovule health with a fluorescent stain under the microscope that highlights wound tissue, called callose, on the ovule surface. We also use a purple stain that allows us to see inside an ovule to the developing embryo in an embryo sac. We plan to measure the amount of callose and size of the embryo and its embryo sac, with and without heat stress. Our project will then enable us to view ovules even earlier in development, and see if the DNA is damaged in cell nuclei. If we see ovules starting to die, we can determine if abortion was caused by heat damage to DNA or if the mother pod was starving the ovules. We also plan to look at gene expression of pollen, tiny pods, their ovules and young embryos, with and without heat stress. We plan to find a way using gene expression from RNA sequencing to identify ovule susceptibility to stress even earlier to the open flower stage. We will use our microscopy methods to measure 18 pea varieties to find the best varieties that can keep ovules alive in a heat wave, so they can be used to develop future pea varieties that can stand up to our warmer summers. Ultimately, our results will identify the best varieties with the most ovule heat-resistance, and even better, add some new experimental methods we can use to simplify and automate for finding better and robust seeds. This research is an industry partnership between the University of Saskatchewan and Saskatchewan Pulse Growers, with collaboration from the federal government.

豌豆植物和农作物对高温和干旱等胁迫敏感，很容易使花和幼豆荚败育，从而降低产量。 胚珠是豆荚内潜在的豌豆种子，在被花粉受精之前。 成功授粉后，每个受精胚珠都含有一个发育成种子的小胚胎。 花和种子的损失可能是因为胚珠容易受到热损伤。 虽然众所周知，授粉对高温和高温天气很挑剔，但我们对胚珠和年轻胚胎在高温下的表现知之甚少。 该项目着眼于豌豆品种，并开发了测量隐藏在花朵内的胚珠热应激的方法。 我们首先对小豆荚及其胚珠使用两种传统方法，这些豆荚和胚珠是在花朵开放四天后从植物中收集的。 在这里，我们可以在显微镜下用荧光染色观察胚珠的健康状况，该染色突出显示胚珠表面的伤口组织，称为胼胝质。 我们还使用紫色染色剂，使我们能够看到胚珠内部以及胚囊中正在发育的胚胎。 我们计划测量有或没有热应激的情况下胼胝质的数量以及胚胎及其胚囊的大小。 我们的项目将使我们能够在发育的早期观察胚珠，并观察细胞核中的 DNA 是否受损。 如果我们看到胚珠开始死亡，我们就可以确定败育是由 DNA 热损伤引起的还是母荚使胚珠挨饿。 我们还计划研究有或没有热应激的花粉、小豆荚、胚珠和幼胚胎的基因表达。 我们计划找到一种方法，利用 RNA 测序的基因表达来识别胚珠对胁迫的敏感性，甚至在开花阶段更早。 我们将使用显微镜方法测量 18 个豌豆品种，以找到能够在热浪中保持胚珠存活的最佳品种，以便它们可用于开发未来能够抵御温暖夏季的豌豆品种。 最终，我们的结果将确定具有最大胚珠耐热性的最佳品种，甚至更好的是，添加一些新的实验方法，我们可以使用它们来简化和自动化，以找到更好、更健壮的种子。 这项研究是萨斯喀彻温大学和萨斯喀彻温豆类种植者协会之间的行业合作伙伴关系，并得到了联邦政府的合作。