Transcriptomic analysis reveals phytohormone and photosynthetic molecular mechanisms of a submerged macrophyte in response to microcystin-LR stress

作者：Li, Qi; Tian, Xueping; Gu, Peng; Yang, Guili; Deng, Hong; Zhang, Jibiao^*; Zheng, Zheng^*

来源：Aquatic Toxicology, 2022, 245: 106119.

DOI：10.1016/j.aquatox.2022.106119

• Microcystin-LR
• Transcriptomics
• Abscisic acid
• Strigolactones
• Pathway

Cyanobacterial blooms impose a substantial risk for submerged macrophytes in aquatic environments. This study investigated the cellular and transcriptomic responses of Vallisneria natans to microcystin-LR (MCLR) exposure, as well as abscisic acid (ABA) and strigolactone (SL), which are the major compounds in signaling networks that regulate plant defense. The results revealed that MCLR significantly (p <0.05) decreased the photosynthetic pigments and significantly (p < 0.05) increased the contents of the ABA and SL stress-related phytohormones under MCLR stress. Related genes involved in the photosynthetic pathways were down-regulated, including psbO, psbP, psbQ and psbR. In the SL biosynthetic pathway of roots under MCLR stress, related genes, such as D27 and CCD7, were down-regulated, while the CCD8 and MAXI genes were up-regulated. In the ABA synthetic pathway, the genes LUT5, ZEP, NCED, ABA2 and AAO3 were up-regulated. Furthermore, a reduction in the content of SL enriched ABA after 3 days under MCLR stress. The potential molecular mechanism of the interactions between SL and ABA were confirmed with the relative up- and down-regulated genes in the pathway, and ABA could play a major role in plant physiology under MCLR stress. This study provides valuable information to understand the stress-related mechanisms of response of submerged macrophytes to cyanobacterial blooms.

• 单位
  贵州大学; 复旦大学; 中国科学院