Light-induced de-etiolation is an important aspect of seedling photomorphogenesis. GOLDEN2 LIKE (GLK) transcriptional regulators are involved in chloroplast development, but to what extent they participate in photomorphogenesis is not clear. Here, we show that ELONGATED HYPOCOTYL5 (HY5) binds to GLK promoters to activate their expression, and also interacts with GLK proteins in Arabidopsis (Arabidopsis thaliana). The chlorophyll content in the de-etiolating Arabidopsis seedlings of the hy5 glk2 double mutants was lower than that in the hy5 single mutant. GLKs inhibited hypocotyl elongation, and the phenotype could superimpose on the hy5 phenotype. Correspondingly, GLK2 regulated the expression of photosynthesis and cell elongation genes partially independent of HY5. Before exposure to light, DE-ETIOLATED 1 (DET1) affected accumulation of GLK proteins. The enhanced etioplast development and photosystem gene expression observed in the det1 mutant were attenuated in the det1 glk2 double mutant. Our study reveals that GLKs act downstream of HY5, or additive to HY5, and are likely quantitatively adjusted by DET1, to orchestrate multiple developmental traits during the light-induced skotomorphogenesis-to-photomorphogenesis transition in Arabidopsis.
Chicoric acid, a phenolic compound derived from plants, exhibits a range of pharmacological activities. Light significantly influences the chicoric acid biosynthesis in Taraxacum mongolicum; however, the transcriptional regulatory network governing this process remains unclear. A combined analysis of the metabolome and transcriptome revealed that blue light markedly enhances chicoric acid accumulation compared to red light.
Injured plant somatic tissues regenerate themselves by establishing shoot or root meristems. In Arabidopsis (Arabidopsis thaliana), a two-step culture system ensures regeneration by first promoting the acquisition of pluripotency and subsequently specifying the fate of new meristems. Although previous studies have reported the importance of phytohormones auxin and cytokinin in determining the fate of new meristems, whether and how environmental factors influence this process remains elusive.
Plants maintain iron (Fe) homeostasis under varying environmental conditions by balancing processes such as Fe uptake, transport and storage. In Arabidopsis, POPEYE (PYE), a basic helix-loop-helix transcription factor (TF), has been shown to play a crucial role in regulating this balance. In recent years, the mechanisms regulating Fe uptake have been well established but the upstream transcriptional regulators of Fe transport and storage are still poorly understood.
In the dynamic environment of plants, the interplay between light-dependent growth and iron nutrition is a recurring challenge. Plants respond to low iron levels by adjusting growth and physiology through enhanced iron acquisition from the rhizosphere and internal iron pool reallocation. Iron deficiency response assays and gene co-expression networks aid in documenting physiological reactions and unraveling gene regulatory cascades, offering insight into the interplay between hormonal and external signaling pathways.
Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610064, China.
The transcription factor ELONGATED HYPOCOTYL5 (HY5) plays a crucial role in seedling growth and development in response to light.
E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) reduces HY5 levels through a process called ubiquitination, but how HY5 is stabilized through deubiquitination was previously unknown.
The enzyme Ub-SPECIFIC PROTEASE 14 (UBP14) was found to interact with HY5, enhancing its stability and promoting photomorphogenesis, while HY5 also promotes UBP14 expression to create a positive feedback loop.
