Ogden Aaron J, Abdali Shadan, Engbrecht Kristin M, Zhou Mowei, Handakumbura Pubudu P
Earth and Biological Sciences Directorate, Pacific Northwest National Laboratories, Richland, WA 99354, USA.
Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
Int J Mol Sci. 2020 Dec 19;21(24):9706. doi: 10.3390/ijms21249706.
Drought is the largest stress affecting agricultural crops, resulting in substantial reductions in yield. Plant adaptation to water stress is a complex trait involving changes in hormone signaling, physiology, and morphology. Sorghum ( (L.) Moench) is a C4 cereal grass; it is an agricultural staple, and it is particularly drought-tolerant. To better understand drought adaptation strategies, we compared the cytosolic- and organelle-enriched protein profiles of leaves from two genotypes, RTx430 and BTx642, with differing preflowering drought tolerances after 8 weeks of growth under water limitation in the field. In agreement with previous findings, we observed significant drought-induced changes in the abundance of multiple heat shock proteins and dehydrins in both genotypes. Interestingly, our data suggest a larger genotype-specific drought response in protein profiles of organelles, while cytosolic responses are largely similar between genotypes. Organelle-enriched proteins whose abundance significantly changed exclusively in the preflowering drought-tolerant genotype RTx430 upon drought stress suggest multiple mechanisms of drought tolerance. These include an RTx430-specific change in proteins associated with ABA metabolism and signal transduction, Rubisco activation, reactive oxygen species scavenging, flowering time regulation, and epicuticular wax production. We discuss the current understanding of these processes in relation to drought tolerance and their potential implications.
干旱是影响农作物的最大胁迫因素，会导致产量大幅下降。植物对水分胁迫的适应是一个复杂的性状，涉及激素信号传导、生理和形态的变化。高粱（(L.) Moench）是一种C4禾本科谷物；它是一种主要农作物，且具有很强的耐旱性。为了更好地理解干旱适应策略，我们比较了两种基因型（RTx430和BTx642）的叶片中富含胞质和细胞器的蛋白质谱，这两种基因型在田间水分限制下生长8周后，开花前的耐旱性不同。与之前的研究结果一致，我们观察到两种基因型中多种热休克蛋白和脱水素的丰度都有明显的干旱诱导变化。有趣的是，我们的数据表明，细胞器蛋白质谱中基因型特异性干旱反应更大，而两种基因型的胞质反应在很大程度上相似。在干旱胁迫下，仅在开花前耐旱基因型RTx430中丰度显著变化的富含细胞器的蛋白质表明了多种耐旱机制。这些机制包括与脱落酸代谢和信号转导、核酮糖-1,5-二磷酸羧化酶/加氧酶激活、活性氧清除、开花时间调控和表皮蜡质生成相关的蛋白质的RTx430特异性变化。我们讨论了目前对这些与耐旱性相关过程的理解及其潜在影响。
