The AP2/ERF transcription factor PtoERF15 confers drought tolerance via JA‐mediated signaling in Populus

Abstract

Summary Drought stress is one of the major limiting factors for the growth and development of perennial trees. Xylem vessels act as the center of water conduction in woody species, but the underlying mechanism of its development and morphogenesis under water‐deficient conditions remains elucidation. Here, we identified and characterized an osmotic stress‐induced ETHYLENE RESPONSE FACTOR 15 (PtoERF15) and its target, PtoMYC2b, which was involved in mediating vessel size, density, and cell wall thickness in response to drought in Populus tomentosa. PtoERF15 is preferentially expressed in differentiating xylem of poplar stems. Overexpression of PtoERF15 contributed to stem water potential maintaining, thus promoting drought tolerance. RNA‐Seq and biochemical analysis further revealed that PtoERF15 directly regulated PtoMYC2b, encoding a switch of JA signaling pathway. Additionally, our findings verify that three sets of homologous genes from NAC (NAM, ATAF1/2, and CUC2) gene family: PtoSND1‐A1/A2, PtoVND7‐1/7‐2, and PtoNAC118/120, as the targets of PtoMYC2b, are involved in the regulation of vessel morphology in poplar. Collectively, our study provides molecular evidence for the involvement of the PtoERF15‐PtoMYC2b transcription cascade in maintaining stem water potential through the regulation of xylem vessel development, ultimately improving drought tolerance in poplar.

A Transcriptomic Analysis Sheds Light on the Molecular Regulation of Wood Formation in Populus trichocarpa during Drought Stress

“…The number of cambium cell layers between internodes was one or two fewer under the drought conditions compared to the control conditions (Figure 2b). These results are consistent with previous studies of xylem in Populus tomentosa [62] and cambium in P. trichocarpa [63].…”

Differentially Expressed Genes Identification of Kohlrabi Seedlings (Brassica oleracea var. caulorapa L.) under Polyethylene Glycol Osmotic Stress and AP2/ERF Transcription Factor Family Analysis

“…The AP2 / ERF transcription factor family is one of the largest transcription factor families in plants, and plays an important role in plant growth and response to stress [ 10 , 35 , 36 , 37 ]. Kong et al [ 38 ] proved that overexpression of PtoERF15 contributed to stem water potential maintenance in response to water deficit in Populus tomentosa , thus promoting drought tolerance. Similarly, Li et al [ 39 ] revealed that overexpression of AtruDREB28 increased tolerance to drought stress by enhancing reactive oxygen species-scavenging capability in Acer truncatum .…”

Understanding AP2/ERF Transcription Factor Responses and Tolerance to Various Abiotic Stresses in Plants: A Comprehensive Review

“…CoDREB-11, CoDREB-14, and CoRAV-01 genes were significantly up-regulated under salinity and drought stress conditions. Kong et al [96] demonstrate that the osmotic stress-induced PtoERF15 and its target gene PtoMYC2b, which is involved in mediating blood vessel size, density, and cell wall thickness in response to drought in poplar, were identified and characterised. Overexpression of PtoERF15 contributes to the maintenance of stem water potential, thereby increasing drought tolerance.…”