Jiang Jinglong, Yang Ni, Li Li, Qin Gongwei, Ren Kexin, Wang Haotian, Deng Jiarui, Ding Dekuan
School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, China.
Chenggu Fruit Industry Technical Guidance Station, Chenggu, China.
Front Plant Sci. 2022 Apr 28;13:875011. doi: 10.3389/fpls.2022.875011. eCollection 2022.
Polyploidy varieties have been reported to exhibit higher stress tolerance relative to their diploid relatives, however, the underlying molecular and physiological mechanisms remain poorly understood. In this study, a batch of autotetraploid were identified from a natural seedling population, and these tetraploid seedlings exhibited greater tolerance to drought stress than their diploids siblings. A global transcriptome analysis revealed that a large number of genes involved in photosynthesis response were enriched in tetraploids under drought stress, which was consistent with the changes in photosynthetic indices including P, gs, T, C, and chlorophyll contents. Compared with diploids, phosphorylation was also modified in the tetraploids after drought stress, as detected through tandem mass tag (TMT)-labeled proteomics. Additionally, tetraploids prioritized the regulation of plant hormone signal transduction at the transcriptional level after drought stress, which was also demonstrated by increased levels of IAA, ABA, and SA and reduced levels of GA3 and JA. Collectively, our results confirmed that the synergistic regulation of photosynthesis response, phosphorylation modification and plant hormone signaling resulted in drought tolerance of autotetraploid germplasm.
据报道，多倍体品种相对于其二倍体亲缘种表现出更高的胁迫耐受性，然而，其潜在的分子和生理机制仍知之甚少。在本研究中，从一个天然幼苗群体中鉴定出一批同源四倍体，这些四倍体幼苗比其二倍体同胞表现出更强的耐旱性。全转录组分析表明，干旱胁迫下四倍体中大量参与光合作用响应的基因富集，这与光合指标包括净光合速率（P）、气孔导度（gs）、蒸腾速率（T）、胞间二氧化碳浓度（C）和叶绿素含量的变化一致。通过串联质谱标签（TMT）标记的蛋白质组学检测发现，与二倍体相比，干旱胁迫后四倍体中的磷酸化也发生了改变。此外，干旱胁迫后四倍体在转录水平上优先调控植物激素信号转导，这也通过生长素（IAA）、脱落酸（ABA）和水杨酸（SA）水平升高以及赤霉素（GA3）和茉莉酸（JA）水平降低得到证实。总体而言，我们的结果证实，光合作用响应、磷酸化修饰和植物激素信号的协同调控导致了同源四倍体种质的耐旱性。
