Department of Agronomy, College of Agriculture, Shanxi Agricultural University, Taigu County, Jinzhong, Shanxi, China.
PLoS One. 2020 Jun 2;15(6):e0234029. doi: 10.1371/journal.pone.0234029. eCollection 2020.
The aim of this study was to determine the effects and underlying molecular mechanisms of humic acid (HA) on foxtail millet (Setaria italica Beauv.) under drought conditions. The rainless climate of the Shanxi Province (37°42'N, 112°58'E) in China provides a natural simulation of drought conditions. Two foxtail millet cultivars, Jingu21 and Zhangza10, were cultivated in Shanxi for two consecutive years (2017-2018) based on a split-plot design. Plant growth, grain quality, and mineral elements were analyzed in foxtail millet treated with HA (50, 100, 200, 300, and 400 mg L-1) and those treated with clear water. Transcriptome sequencing followed by bioinformatics analysis was performed on plants in the normal control (CK), drought treatment (D), and drought + HA treatment (DHA) groups. Results were verified using real-time quantitative PCR (RT-qPCR). HA at a concentration of 100-200 mg L-1 caused a significant increase in the yield of foxtail millet and had a positive effect on dry weight and root-shoot ratio. HA also significantly increased P, Fe, Cu, Zn, and Mg content in grains. Moreover, a total of 1098 and 409 differentially expressed genes (DEGs) were identified in group D vs. CK and D vs. DHA, respectively. A protein-protein interaction network and two modules were constructed based on DEGs (such as SETIT_016654mg) between groups D and DHA. These DEGs were mainly enriched in the metabolic pathway. In conclusion, HA (100 mg L-1) was found to promote the growth of foxtail millet under drought conditions. Furthermore, SETIT_016654mg may play a role in the effect of HA on foxtail millet via control of the metabolic pathway. This study lays the foundation for research into the molecular mechanisms that underlie the alleviating effects of HA on foxtail millet under drought conditions.
本研究旨在确定腐殖酸（HA）在干旱条件下对谷子（Setaria italica Beauv.）的影响及其潜在的分子机制。中国山西省（37°42'N，112°58'E）的少雨气候为干旱条件提供了自然模拟。根据裂区设计，在山西连续两年（2017-2018 年）种植了两个谷子品种，金谷 21 号和张杂 10 号。用 HA（50、100、200、300 和 400mgL-1）和清水处理谷子，分析谷子的生长、籽粒品质和矿物元素。对正常对照（CK）、干旱处理（D）和干旱+HA 处理（DHA）组的植物进行转录组测序和生物信息学分析。采用实时定量 PCR（RT-qPCR）进行验证。浓度为 100-200mgL-1 的 HA 显著增加了谷子的产量，对干重和根-茎比有积极影响。HA 还显著增加了籽粒中 P、Fe、Cu、Zn 和 Mg 的含量。此外，在 D 与 CK 和 D 与 DHA 相比的组中，分别鉴定出 1098 和 409 个差异表达基因（DEGs）。基于 DEGs（如 SETIT_016654mg）构建了 D 与 DHA 之间的蛋白质-蛋白质相互作用网络和两个模块。这些 DEGs 主要富集在代谢途径中。总之，在干旱条件下，HA（100mgL-1）被发现能促进谷子的生长。此外，SETIT_016654mg 可能通过控制代谢途径在 HA 对谷子的作用中发挥作用。本研究为研究 HA 缓解谷子干旱胁迫的分子机制奠定了基础。
