NAC-mediated membrane lipid remodeling negatively regulates fruit cold tolerance

Chunbo Song; Mengbo Wu; Ying Zhou; Zehao Gong; Weiwei Yu; Yi Zhang; Zhenfeng Yang

doi:10.1093/hr/uhac039

NAC-mediated membrane lipid remodeling negatively regulates fruit cold tolerance

Hortic Res. 2022 May 4:9:uhac039. doi: 10.1093/hr/uhac039. eCollection 2022.

Authors

Chunbo Song^{1

2}, Mengbo Wu³, Ying Zhou⁴, Zehao Gong³, Weiwei Yu⁴, Yi Zhang⁴, Zhenfeng Yang¹

Affiliations

¹ College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China.
² College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong 266100, China.
³ Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China.
⁴ State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.

Abstract

Low temperatures are known to destroy cell membranes' structural integrity by affecting the remodeling of their phospholipids. Fruits stored at low temperature are prone to chilling injury, characterized by discoloration, absence of ripening, surface pitting, growth inhibition, flavor loss, decay, and wilting. Phosphatidic acid, a vital second-messenger lipid in plants, is known to accumulate in response to different kinds of stress stimuli. However, the regulatory mechanism of its production from the degradation of phospholipids remains poorly understood. We identified two cold-responsive NAC (NAM/ATAF1/CUC2) transcription factors from bananas, namely, MaNAC25 and MaNAC28, which negatively regulated cold tolerance in banana fruits by upregulating the expression of phospholipid degradation genes in banana fruits. Furthermore, MaNAC25 and MaNAC28 formed a positive feedback loop to induce phospholipid degradation and produce phosphatidic acid. In contrast, ethylene directly inhibited the degradation of phospholipids in banana and transgenic tomato fruits. In addition, ethylene reduced the activity of MaNAC25 and MaNAC28, thereby inhibiting phospholipid degradation. To conclude, NAC-mediated membrane lipid remodeling negatively regulates the cold tolerance of banana and transgenic tomato fruits.