Liu Hui, Sun Hongmei, Bao Lijun, Han Shuhua, Hui Tian, Zhang Rui, Zhang Minjuan, Su Chao, Qian Yonghua, Jiao Feng
The Sericultural and Silk Research Institute, College of Animal Science and Technology, Northwest A&F University, Xianyang, China.
Shaanxi Key Laboratory of Sericulture, Ankang University, Ankang, China.
Front Plant Sci. 2021 Oct 6;12:720452. doi: 10.3389/fpls.2021.720452. eCollection 2021.
The improvement of a plant's tolerance to drought is a major endeavor in agriculture. Polyploid plants often exhibit enhanced stress tolerance relative to their diploid progenitor, but the matching stress tolerance is still little understood. Own-rooted stem cuttings of mulberry (Morus alba L.) cultivar Shinichinose (2n = 2x = 28) and Shaansang-305 (2n = 3x = 42) were used in this study, of which the latter (triploid) has more production and application purposes. The responses of triploid Shaansang-305 and diploid progenitor ShinIchinose under drought stress were compared through an investigation of their physiological traits, RNA-seq, and secondary metabolome analysis. The results showed that the triploid exhibited an augmented content and a better stress tolerance phenotype under severe drought stress. Further, in the triploid plant some genes (, and ) and gene related to ABA signaling showed significantly upregulated expression. Interestingly, the triploid accumulated higher levels of RWC and SOD activity, as well as more wax on the leaf surface, . Our results suggest triploid plants may better with drought events. Furthermore, the flavonoid metabolism involved in drought resistance identified here may be of great value to medicinal usage of mulberry. The findings presented here could have substantial implications for future studies of crop breeding.
提高植物的耐旱性是农业领域的一项重要工作。多倍体植物相对于其二倍体祖先往往表现出更强的胁迫耐受性，但对其相应的胁迫耐受性仍知之甚少。本研究使用了桑树（Morus alba L.）品种新千穗（2n = 2x = 28）和陕桑305（2n = 3x = 42）的自根茎插条，其中后者（三倍体）具有更多的生产和应用价值。通过对三倍体陕桑305和二倍体祖先新千穗的生理特性、RNA测序和次生代谢组分析，比较了它们在干旱胁迫下的反应。结果表明，三倍体在严重干旱胁迫下表现出更高的含量和更好的胁迫耐受表型。此外，在三倍体植物中，一些与ABA信号相关的基因（、和）和基因表达显著上调。有趣的是，三倍体积累了更高水平的相对含水量和超氧化物歧化酶活性，以及叶表面更多的蜡质。我们的结果表明，三倍体植物可能更能适应干旱事件。此外，这里鉴定出的参与抗旱的黄酮类代谢可能对桑树的药用具有重要价值。本文的研究结果可能对未来作物育种研究具有重要意义。
