le Roux Marlon-Schylor L, Burger N Francois V, Vlok Maré, Kunert Karl J, Cullis Christopher A, Botha Anna-Maria
Department of Genetics, University of Stellenbosch, Stellenbosch, South Africa.
Proteomics Unit, Central Analytical Facilities, University of Stellenbosch, Stellenbosch, South Africa.
Front Plant Sci. 2020 Jul 14;11:1053. doi: 10.3389/fpls.2020.01053. eCollection 2020.
Random mutagenesis was applied to produce a new wheat mutant (RYNO3926) with superior characteristics regarding tolerance to water deficit stress induced at late booting stage. The mutant also displays rapid recovery from water stress conditions. Under water stress conditions mutant plants reached maturity faster and produced more seeds than its wild type wheat progenitor. Wild-type Tugela DN plants died within 7 days after induction of water stress induced at late booting stage, while mutant plants survived by maintaining a higher relative moisture content (RMC), increased total chlorophyll, and a higher photosynthesis rate and stomatal conductance. Analysis of the proteome of mutant plants revealed that they better regulate post-translational modification (SUMOylation) and have increased expression of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) proteins. Mutant plants also expressed unique proteins associated with dehydration tolerance including abscisic stress-ripening protein, cold induced protein, cold-responsive protein, dehydrin, Group 3 late embryogenesis, and a lipoprotein (LAlv9) belonging to the family of lipocalins. Overall, our results suggest that our new mutant RYNO3936 has a potential for inclusion in future breeding programs to improve drought tolerance under dryland conditions.
采用随机诱变技术培育出一种新的小麦突变体（RYNO3926），该突变体在孕穗后期诱导的水分亏缺胁迫耐受性方面具有优良特性。该突变体在水分胁迫条件下也能迅速恢复。在水分胁迫条件下，突变体植株比其野生型小麦亲本成熟更快，结籽更多。野生型图盖拉DN植株在孕穗后期诱导水分胁迫后7天内死亡，而突变体植株通过保持较高的相对含水量（RMC）、增加总叶绿素含量、提高光合速率和气孔导度得以存活。对突变体植株蛋白质组的分析表明，它们能更好地调节翻译后修饰（SUMO化），并增加了1,5-二磷酸核酮糖羧化酶/加氧酶（RuBisCO）蛋白的表达。突变体植株还表达了与脱水耐受性相关的独特蛋白质，包括脱落酸胁迫成熟蛋白、冷诱导蛋白、冷响应蛋白、脱水素、第3组成熟后期胚胎发生蛋白，以及一种属于脂质运载蛋白家族的脂蛋白（LAlv9）。总体而言，我们的结果表明，我们新的突变体RYNO3936有潜力纳入未来的育种计划，以提高旱地条件下的耐旱性。
