Overexpressing phytochrome interacting factor 8 of Myrothamnus flabellifolia enhanced drought and salt tolerance in Arabidopsis

Authors: HUANG, ZHUO - Sichuan Agricultural University; TANG, RONG - Sichuan Agricultural University; YI, XIN - Sichuan Agricultural University; XU, WENXIN - Sichuan Agricultural University; ZHU, PEILEI - Sichuan Agricultural University; Jiang, Cai-Zhong

Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/2022
Publication Date: 7/24/2022
Citation: Huang, Z., Tang, R., Yi, X., Xu, W., Zhu, P., Jiang, C. 2022. Overexpressing phytochrome interacting factor 8 of Myrothamnus flabellifolia enhanced drought and salt tolerance in Arabidopsis. International Journal of Molecular Sciences. 23(15). Article 8155. https://doi.org/10.3390/ijms23158155.
DOI: https://doi.org/10.3390/ijms23158155

Interpretive Summary: Abiotic stresses such as drought, salinity, and extreme temperature detrimentally impact plants' growth, development, and yield. In order to respond to diverse abiotic stresses and increase the probability of survival, plants have evolved sophisticated mechanisms to regulate their responses to stresses, which are controlled by complex regulating networks involving a wide range of genes, in which genes encoding transcription factors (TFs) are among the most pivotal regulator to strengthen the plant adverse resistance. It has been proved that overexpression of a single transcription factor can significantly improve the stress tolerance of transgenic plants. Consequently, it has great significance to explore the TF genes related to plant stress tolerance for the genetic improvement of plants.

Technical Abstract: Myrothamnus flabellifolia is the only woody resurrection plant found in the world and could survive from long term desiccation. Therefore, M. flabellifoli could be considered as a valuable resource for study of plant adaptation to abiotic stress. However, few genes related to its drought tolerance had been functionally characterized and the molecular mechanisms underlying the stress tolerance of M. flabellifolia are largely unknown. Phytochrome interacting factor (PIF) family is a group of basic helix-loop-helix (bHLH) transcription factor and function as the core regulator in plant growth and development. However, less is known of its participation in abiotic stress response. In this study, we isolated and characterized of a dehydration-inducible PIF gene MfPIF8 from M. flabellifolia. Heterologous expression of MfPIF8 in Arabidopsis enhanced tolerance to drought and salinity stresses at seedling and adult stages. It significantly increased primary root length and stomatal aperture (ration of length/width) under stress treatment, and decreased water loss rate. Compared with WT, The transgenic lines overexpressing MfPIF8 exhibited higher chlorophyll content and lower Malondialdehyde accumulation. The abilities of osmotic adjustment and reactive oxygen species scavenging were also enhanced in MfPIF8 transgenic lines. These results suggested that MfPIF8 may participate in positive regulation of abiotic stress responses. Further investigation of its mechanism is need in the future.