Recently, Associate Professor Ziqiang Zhu’s research team revealed the physiological role for Jasmonate in the suppression of skotomorphogenesis.
Jasmonate (JA), a major defense hormone in plants which can protect plants against necrotrophic fungi and herbivores and regulate a variety of plantgrowth and developmental processes. So far, whether JA is involved in the regulation of skotomorphogenesis remains unknown.
A germinating seedling undergoes skotomorphogenesis to emerge from the soil and reach forlight. During this phase, the cotyledons are closed, and the hypocotyl elongates. Uponexposure to light, the seedling rapidly switches to photomorphogenesis by opening its cotyledons and suppressing hypocotyl elongation.The E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) is critical for maintaining skotomorphogenesis.
The findings are as follows:JA suppresses hypocotyl elongation and stimulates cotyledonopening in etiolated seedlings, partially phenocopying cop1 mutants in the dark.JA stabilizes several COP1-targeted transcription factors in a COP1-dependent manner. RNA-seq analysis further defines a JA-light co-modulated and cop1-dependent transcriptome, which is enriched for auxin-responsive genes and genes participating in cell wallmodification. JA suppresses COP1 activity through at least two distinct mechanisms:decreasing COP1 protein accumulation in the nucleus and reducing the physical interactionbetween COP1 and its activator, SUPPRESSOR OF PHYTOCHROME A-105 1 (SPA1).
Their work reveals an un-reported role of JA and uncovered its underlyingregulatory mechanisms on COP1 protein, which is of great importance in studying the integration of plant between environmental factors and endogenous hormone signaling pathways.
This research is published online March 21 in the international famous journal The Plant Journal (One of the three leading journals in the botany field, 5-Year IF=6.468). This is also the first time for Nanjing Normal University to publish a research paper inThe Plant Journalas the first signature unit. The first author of this paper is master candidate Yuyu Zheng and the corresponding author is associate professor Ziqiang Zhu.
This research was funded by the National Natural Science Foundation of China (NSFC), the Natural Science Foundation for Young Scholars of Jiangsu Province, the Biological Preponderant Discipline of Jiangsu Province, “Qinglan Project” of Jiangsu Province, "Hundreds of Youth Leader Talent Training Plan" in Nanjing Normal University.