University of North Carolina Wilmington, Department of Biology and Marine Biology, Department of Mathematics and Statistics, Wilmington, NC, USA.
North Carolina Department of Health and Human Services, State Laboratory of Public Health, Raleigh, NC, USA.
Sci Rep. 2019 Jul 17;9(1):10392. doi: 10.1038/s41598-019-46839-9.
Plants are increasingly exposed to high temperatures, which can cause accumulation of unfolded protein in the endoplasmic reticulum (ER). This condition, known as ER stress, evokes the unfolded protein response (UPR), a cytoprotective signaling pathway. One important branch of the UPR is regulated by splicing of bZIP60 mRNA by the IRE1 stress sensor. There is increasing evidence that commercial plant growth regulators may protect against abiotic stressors including heat stress and drought, but there is very little mechanistic information about these effects or about the regulatory pathways involved. We evaluated evidence in the B73 Zea mays inbred for differences in the activity of the UPR between permissive and elevated temperature in conjunction with plant growth regulator application. Treatment with elevated temperature and plant growth regulators increased UPR activation, as assessed by an increase in splicing of the mRNA of the IRE1 target bZIP60 following paclobutrazol treatment. We propose that plant growth regulator treatment induces bZIP60 mRNA splicing which 'primes' plants for rapid adaptive response to subsequent endoplasmic reticulum-stress inducing conditions.
植物越来越多地暴露在高温下，这会导致内质网（ER）中未折叠蛋白的积累。这种情况被称为内质网应激，会引发未折叠蛋白反应（UPR），这是一种细胞保护信号通路。UPR 的一个重要分支是由 IRE1 应激传感器对 bZIP60 mRNA 的剪接来调节的。越来越多的证据表明，商业植物生长调节剂可能有助于抵御非生物胁迫因素，包括高温和干旱，但关于这些作用或涉及的调节途径的机制信息却非常有限。我们评估了 B73 Zea mays 近交系在允许温度和升高温度下 UPR 活性差异方面的证据，同时结合了植物生长调节剂的应用。用升高的温度和植物生长调节剂处理会增加 UPR 的激活，这可以通过用多效唑处理后 IRE1 靶标 bZIP60 的 mRNA 剪接增加来评估。我们提出，植物生长调节剂处理诱导 bZIP60 mRNA 的剪接，从而使植物能够快速适应随后的内质网应激诱导条件。
