Knockout of Auxin Response Factor SlARF4 Improves Tomato Resistance to Water Deficit

International Journal of Molecular Sciences

Caiyu Wu¹  Lin Chen¹  Yanwei Hao¹  Canye Yu¹  Mengyi Chen¹  Xiaojuan Liu¹  Riyuan Chen¹  Guojian Hu¹  Xiaoyang Zhu¹  Mondher Bouzayen²  Mohammed Zouine² 

[1] Key Laboratory of Horticultural Crop Biology and Germplasm Innovation in South China, Ministry of Agriculture, College of Horticulture, South China Agricultural University, Guangzhou 510642, China;Laboratory Genomics and Biotechnology of Fruits, INRA, Toulouse INP, University of Toulouse, 31320 Castanet Tolosan, France;

关键词: SlARF4;    tomato;    water deficit;    drought;    ABA;    auxin;   

DOI  :  10.3390/ijms22073347

来源: DOAJ

【 摘 要 】

Auxin response factors (ARFs) play important roles in various plant physiological processes; however, knowledge of the exact role of ARFs in plant responses to water deficit is limited. In this study, SlARF4, a member of the ARF family, was functionally characterized under water deficit. Real-time fluorescence quantitative polymerase chain reaction (PCR) and β-glucuronidase (GUS) staining showed that water deficit and abscisic acid (ABA) treatment reduced the expression of SlARF4. SlARF4 was expressed in the vascular bundles and guard cells of tomato stomata. Loss of function of SlARF4 (arf4) by using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 (CRISPR/Cas 9) technology enhanced plant resistance to water stress and rehydration ability. The arf4 mutant plants exhibited curly leaves and a thick stem. Malondialdehyde content was significantly lower in arf4 mutants than in wildtype plants under water stress; furthermore, arf4 mutants showed higher content of antioxidant substances, superoxide dismutase, actual photochemical efficiency of photosystem II (PSII), and catalase activities. Stomatal and vascular bundle morphology was changed in arf4 mutants. We identified 628 differentially expressed genes specifically expressed under water deficit in arf4 mutants; six of these genes, including ABA signaling pathway-related genes, were differentially expressed between the wildtype and arf4 mutants under water deficit and unlimited water supply. Auxin responsive element (AuxRE) elements were found in these genes’ promoters indicating that SlARF4 participates in ABA signaling pathways by regulating the expression of SlABI5/ABF and SCL3, thereby influencing stomatal morphology and vascular bundle development and ultimately improving plant resistance to water deficit.

【 授权许可】

Unknown