Comparative proteomics analyses of intraspecific differences in the response of Stipa purpurea to drought

Xiong Li; Yunqiang Yang; Shihai Yang; Xudong Sun; Xin Yin; Youjie Zhao; Yongping Yang

doi:10.1016/j.pld.2016.03.002

Comparative proteomics analyses of intraspecific differences in the response of Stipa purpurea to drought

Plant Divers. 2016 Jun 11;38(2):101-117. doi: 10.1016/j.pld.2016.03.002. eCollection 2016 Apr.

Authors

Xiong Li^{1

2}, Yunqiang Yang^{1

2}, Shihai Yang³, Xudong Sun^{1

2}, Xin Yin^{1

2

4}, Youjie Zhao⁵, Yongping Yang^{1

2}

Affiliations

¹ Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
² Plant Germplasm and Genomics Center, Germplasm Bank of Wild Species in Southwest of China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
³ State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
⁴ University of Chinese Academy of Sciences, Beijing, 100049, China.
⁵ Computer and Information Department, Southwest Forestry University, Kunming, 650224, China.

Abstract

Stipa purpurea is widely distributed along a large precipitation gradient on the Tibetan Plateau. This implies that S. purpurea from different populations may have different responses to drought stress. To explore this we compared the morphological and physiological changes of S. purpurea seedlings cultivated from seeds from Gar County and Nagqu County after 7 and 14 days of drought stress and subsequent re-watering. The results showed that S. purpurea plants from the more arid Gar area were more tolerant to drought stress than that from Nagqu. To investigate the potential mechanisms underlying this difference, we used iTRAQ quantitative proteomics technology to analyze protein dynamics in S. purpurea samples treated with 7 days of drought stress and subsequent re-watering. The results indicated that, during the process of drought and re-watering treatments, there were differentially expressed proteins in either or both S. purpurea populations. These differential proteins were divided into 24 functional categories that were mainly associated with stress response, the antioxidant system, photosynthesis, carbohydrate metabolism, and post-translational modifications. According to these results, we concluded that the molecular basis of stronger drought resistance likely lies in the specific up-regulation or higher expression of many proteins involved in stress response, the antioxidant system, post-translational modification and osmotic regulation in S. purpurea from Gar County compared with that from Nagqu. This study improves our understanding of the intraspecific differences in drought resistance within S. purpurea populations, which helps to understand the distribution of S. purpurea along the moisture gradient, as well as the effect of climate change on this species.

Keywords: Adaptation; CDPK, calcium-dependent protein kinase; DREB, dehydration responsive element binding protein; DW, dry weight; Drought; GR, Gar Country; GR-C/-D/-R, GR-Control/-Drought/-Recovery; HSP, heat shock protein; LEA, late embryogenesis abundant protein; MAPK, mitogen activated protein kinase; NQ, Nagqu Country; NQ-C/-D/-R, NQ-Control/-Drought/-Recovery; Proteomics; ROS, reactive oxygen species; RWC, relative water content; Stipa purpurea; Tibetan Plateau; iTRAQ, isobaric tag for relative and absolute quantitation.