Liu Haipei, Able Amanda J, Able Jason A
School of Agriculture, Food & Wine, Waite Research Institute, The University of Adelaide, Urrbrae SA5064, Australia.
Plants (Basel). 2020 Feb 4;9(2):189. doi: 10.3390/plants9020189.
Water deficiency and heat stress can severely limit crop production and quality. Stress imposed on the parents during reproduction could have transgenerational effects on their progeny. Seeds with different origins can vary significantly in their germination and early growth. Here, we investigated how water-deficit and heat stress on parental durum wheat plants affected seedling establishment of the subsequent generation. One stress-tolerant and one stress-sensitive Australian durum genotype were used. Seeds were collected from parents with or without exposure to stress during reproduction. Generally, stress on the previous generation negatively affected seed germination and seedling vigour, but to a lesser extent in the tolerant variety. Small RNA sequencing utilising the new durum genome assembly revealed significant differences in microRNA (miRNA) expression in the two genotypes. A bioinformatics approach was used to identify multiple miRNA targets which have critical molecular functions in stress adaptation and plant development and could therefore contribute to the phenotypic differences observed. Our data provide the first confirmation of the transgenerational effects of reproductive-stage stress on germination and seedling establishment in durum wheat. New insights gained on the epigenetic level indicate that durum miRNAs could be key factors in optimising seed vigour for breeding superior germplasm and/or varieties.
水分亏缺和热胁迫会严重限制作物产量和品质。繁殖期施加于亲本的胁迫可能会对其后代产生跨代影响。不同来源的种子在发芽和早期生长方面可能有显著差异。在此，我们研究了硬粒小麦亲本植株上的水分亏缺和热胁迫如何影响后代的幼苗建立。使用了一种耐胁迫和一种对胁迫敏感的澳大利亚硬粒小麦基因型。从繁殖期经受或未经受胁迫的亲本收集种子。一般来说，上一代的胁迫对种子萌发和幼苗活力有负面影响，但在耐胁迫品种中影响较小。利用新的硬粒小麦基因组组装进行的小RNA测序揭示了两种基因型中微小RNA（miRNA）表达的显著差异。采用生物信息学方法鉴定了多个在胁迫适应和植物发育中具有关键分子功能的miRNA靶标，因此可能导致观察到的表型差异。我们的数据首次证实了繁殖期胁迫对硬粒小麦萌发和幼苗建立的跨代影响。在表观遗传水平上获得的新见解表明，硬粒小麦miRNA可能是优化种子活力以培育优良种质和/或品种的关键因素。
