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Rahneshan, Z.

Publications and source records attributed to Rahneshan, Z..

2 recordsLinked to original sources
bioRxiv2026

A drought stress-induced MYB transcription factor regulates pavement cell shape in leaves of European aspen (Populus tremula)

The leaf pavement cells of many plant species develop fascinating jigsaw puzzle-like shapes in which neighboring cells interdigitate with each other, providing an ideal model for the study of cell shape acquisition. We analyzed pavement cell shape complexity in a natural population of European aspen (Populus tremula) genotypes and then used a genome-wide association study (GWAS) approach to identify a new candidate gene in cell shape regulation, Potra2n8c18226, encoding the transcription factor MYB305a. We subsequently validated a role for MYB305a in regulating aspen leaf pavement cell shape. We then demonstrated that drought conditions strongly induced MYB305a promoter expression in these cells and provided evidence implying that MYB305a plays a role in simplification of the cell shape in response to drought stress. Finally, we demonstrated negative correlations of pavement cell shape complexity with water-use efficiency, as well as with average precipitation, latitude and longitude of the genotypes original sampling sites in the natural European aspen population. Taken together, our results suggest that climatic variables affect the shape complexity of pavement cells in aspen leaf and provide a first step towards unravelling the molecular mechanisms controlling pavement cell shape acquisition in this species in response to environmental conditions, by implicating the involvement of the transcription factor MY305a.

plant biology↗
bioRxiv2019

Cytokinin induction by the Jasmonate-induced AP2/ERF115 represses adventitious rooting in Arabidopsis

Jasmonate (JA), an oxylipin-derived phytohormone, plays crucial roles not only in plant immunity and defense against herbivorous insects but also in plant growth and developmental processes, including regeneration and organogenesis. However, the mechanistic basis of its mode of action and precise role in integrating other signaling cues are poorly understood. Here we provide genetic evidences that JA signaling acts in both NINJA-dependent and -independent modulation of the transcriptional activity of MYC transcription factors involved in the inhibition of adventitious root initiation (ARI). Our data show that NINJA-dependent JA signaling in pericycle cells blocks early events of ARI. Moreover, transcriptomic comparison of ninja-1myc2-322B double mutant (which produce extremely few ARs) and wild type seedlings identified a novel molecular network governed by the APETALA2/ETHYLENE RESPONSE FACTOR 115 (ERF115) transcription factor. We demonstrate that JA-induced ERF115 activates the cytokinin signaling machinery and thereby represses ARI. Altogether, our results reveal a molecular network involving cooperative crosstalk between JA and CK machineries that inhibits ARI.

plant biology↗