Horticulturae (Nov 2021)

Key Proteins and Metabolic Pathways Involved in 24-Epibrasionlide Improving Drought Tolerance of <i>Rhododendron delavayi</i> Franch

  • Yan-Fei Cai,
  • Lu Zhang,
  • Lv-Chun Peng,
  • Shi-Feng Li,
  • Jie Song,
  • Wei-Jia Xie,
  • Ji-Hua Wang

DOI
https://doi.org/10.3390/horticulturae7110501
Journal volume & issue
Vol. 7, no. 11
p. 501

Abstract

Read online

Rhododendron delavayi Franch. is a famous ornamental plant. However, seasonal drought caused by a monsoon climate seriously limits its growth and flowering performance in urban gardens. Our previous study has found that brassinosteroids (BRs) can improve the tolerance of R. delavayi to drought stress. Here, we employed a data-independent acquisition (DIA) approach to compare the protein expression profiles under drought treatment (D) and pre-treatment with BR before drought treatment (BR). With an increase in drought stress, the net photosynthetic rate, stomatal conductance, and transpiration rate in the BR treatment showed more stable changes that were significantly higher than those in the D treatment. However, the contents of malondialdehyde, soluble sugar, soluble protein, and the activity of superoxide dismutase (SOD), peroxidase, and catalase showed opposite trends. The pre-treatment with BR alleviated the negative effect of drought stress on the photosynthetic performance of R. delavayi. A total of 3453 differentially expressed proteins (DEPs) were identified, and 683 DEPs were significantly expressed in the D and BR treatments. The DEPs uniquely expressed in the BR treatment participated in the pathways of “ribosome”, “ether lipid metabolism”, “photosynthesis”, and “oxidative phosphorylation”. The improvement effect of the BR treatment on the drought tolerance of R. delavayi was mainly attributed to improved photosynthesis by alleviating stomatal closure and oxidative stress, maintaining the integrity and stability of the ribosomal complex to mediate protein synthesis and the balance between energy metabolism and carbon metabolism. Our study presents a comprehensive understanding of the key proteins and metabolic pathways related to the response of R. delavayi to drought and will contribute to the breeding of drought-tolerant rhododendrons.

Keywords