Fecha de publicación: 05/10/2024 Fuente: ISHS (International Society for Horticultural Science) Post date: Saturday 5 October 2024
Author:
ISHS Secretariat

The phytohormone ethylene plays a pivotal role in climacteric fruit ripening. However, the knowledge on molecular regulation of ethylene biosynthesis remains limited in pears. In our study, a new basic helix-loop-helix transcription factor, PbbHLH164, was identified based on the transcriptome analysis of developing and ripening fruit. Transient expression in pear fruits and genetic transformation in callus demonstrated that PbbHLH164 can promote ethylene synthesis by directly binding to the promoter of 1-aminocyclopropane-1-carboxylate synthase, PbACS1b, leading to the increase of ethylene production and an acceleration in fruit ripening. PbbHLH164 was found to physically interact with a ubiquitin-associated protein PbRAD23C/D.1, and this interaction attenuated the ability of PbbHLH164 to enhance the activity of the PbACS1b promoter. Notably, PbRAD23C/D.1 was involved in the degradation of PbbHLH164, and this degradation was inhibited by a ubiquitin proteasome inhibitor MG132. Unlike PbbHLH164, PbRAD23C/D.1 exhibits higher expression levels in developing fruit compared to ripening fruit. These results suggest that the increase of ethylene production during the ripening of pear results from the up-regulated expression of PbbHLH164 and the down-regulated expression of PbRAD23C/D.1. Our findings provide new insights into the molecular regulation of ethylene biosynthesis during fruit ripening.
Zhihua Guo won the ISHS Young Minds Award for the best poster presentation at the V International Symposium on Biotechnology and Molecular Breeding in Horticultural Species in China in June 2024.
Zhihua Guo, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu Province, China, e-mail: 976128942@qq.com
The article is available in Chronica HorticulturaeTags: pear fruit ripeningCategories: Young Minds Award Winners