The CaCIPK3 gene positively regulates drought tolerance in pepper

Xiao Ma,Wen-Xian Gai,Yang Li,Zhen-Hui Gong,Chuang Li

doi:10.1038/s41438-021-00651-7

Xiao Ma, Wen-Xian Gai + Show 3 more

Open Access

https://doi.org/10.1038/s41438-021-00651-7

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Abstract

Drought stress is a major agricultural problem restricting the growth, development, and productivity of plants. Calcineurin B-like proteins (CBLs) and CBL-interacting protein kinases (CIPKs) significantly influence the plant response to different stresses. However, the molecular mechanisms of CBL–CIPK in the drought stress response of pepper are still unknown. Here, the function of CaCIPK3 in the regulation of drought stress in pepper (Capsicum annuum L.) was explored. Transcriptomic data and quantitative real-time PCR (qRT-PCR) analysis revealed that CaCIPK3 participates in the response to multiple stresses. Knockdown of CaCIPK3 in pepper increased the sensitivity to mannitol and methyl jasmonate (MeJA). Transient overexpression of CaCIPK3 improved drought tolerance by enhancing the activities of the antioxidant system and positively regulating jasmonate (JA)-related genes. Ectopic expression of CaCIPK3 in tomato also improved drought and MeJA resistance. As the CaCIPK3-interacting partner, CaCBL2 positively influenced drought resistance. Additionally, CaWRKY1 and CaWRKY41 directly bound the CaCIPK3 promoter to influence its expression. This study shows that CaCIPK3 acts as a positive regulator in drought stress resistance via the CBL–CIPK network to regulate MeJA signaling and the antioxidant defense system.

Highlights

Pepper (Capsicum annuum L.) is an economically important horticultural plant belonging to the Solanaceae family
CaCIPK3 encodes a protein with 440 amino acid residues and a molecular weight of 49.81 kDa
To explore the position and potential function of CaCIPK3, the gene was fused between the CaMV35S promoter and green fluorescent protein (GFP) (Supplementary Fig. S1B)

Summary

Introduction

Pepper (Capsicum annuum L.) is an economically important horticultural plant belonging to the Solanaceae family. The harvested area and production of pepper have increased significantly in recent years. The latest FAO data show that the annual production of pepper was 38.03 million tons worldwide in 20192. Plants need to evolve complex mechanisms against diverse stresses under current global environmental deterioration[3]. In the northwest region of China, drought is a critical stress and significantly affects plant production. Exploring the molecular mechanisms of plants under drought stress can help enhance drought tolerance. Molecules such as calcium (Ca2+), reactive oxygen species (ROS), and abscisic acid (ABA) act as long-distance messengers in the regulation of drought stress[4]

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