Strawberry <i>FaNAC2</i> Enhances Tolerance to Abiotic Stress by Regulating Proline Metabolism

oleh: Jiahui Liang, Jing Zheng, Ze Wu, Hongqing Wang

Format: Article
Diterbitkan: MDPI AG 2020-10-01

Deskripsi

The quality and yields of strawberry plants are seriously affected by abiotic stress every year. NAC (NAM, ATAF, CUC) transcription factors are plant-specific, having various functions in plant development and response to stress. In our study, <i>FaNAC2</i> from strawberry (<i>Fragaria × ananassa</i>, cultivar “Benihoppe”) was isolated and found to be a member of the ATAF sub-family, belonging to the NAC family of transcription factors. <i>FaNAC2</i> was strongly expressed in the shoot apical meristem and older leaves of strawberries, and was induced by cold, high salinity, and drought stress. To investigate how <i>FaNAC2</i> functions in plant responses to abiotic stress, transgenic <i>Nicotiana benthamiana</i> plants ectopically overexpressing <i>FaNAC2</i> were generated. The transgenic plants grew better under salt and cold stress, and, during simulated drought treatment, these transgenic lines not only grew better, but also showed higher seed germination rates than wild-type plants. Gene expression analysis revealed that key genes in proline biosynthesis pathways were up-regulated in <i>FaNAC2</i> overexpression lines, while its catabolic pathway genes were down-regulated and proline was accumulated more with the overexpression of <i>FaNAC2</i> after stress treatments. Furthermore, the gene expression of abscisic acid biosynthesis was also promoted. Our results demonstrate that <i>FaNAC2</i> plays an important positive role in response to different abiotic stresses and may be further utilized to improve the stress tolerance of strawberry plants.