Hoefgen, R. | Search bioRxiv

bioRxiv2025

SNRK3.15 is a crucial component of the sulfur deprivation response in Arabidopsis thaliana

Sulfate deprivation (-S) results in numerous metabolic and phenotypic alterations in plants. Kinases are often key players in transducing nutrient status signals to molecular components involved in metabolic and developmental program regulation, but despite the physiological importance of sulfur, to date, no signaling kinases have been identified in sulfur-deficiency signaling response programs. Here we show that the serine/threonine protein kinase CIPK14/SNRK3.15 plays a regulatory role in the -S response in Arabidopsis thaliana seedlings. Multiple molecular and physiological responses to -S are attenuated in snrk3.15 mutants, including both early adaptive responses and later emergency salvage processes including nutrient deficiency induced senescence. When grown in soil with sufficient sulfur supply, snrk3.15 mutants showed no clear phenotypes, including no difference in seed sulfur content. Lastly, the proteome dataset generated from Col-0 and snrk3.15.1 Arabidopsis seedlings under -S conditions for this project is the first of its kind and will be a valuable research resource. Proteomics data are available via ProteomeXchange with identifier PXD046612.

plant biology↗

bioRxiv2021

In silico analysis of cis-elements and identification of transcription factors putatively involved in the regulation of the OAS cluster genes SDI1 and SDI2

A. thaliana sulfur deficiency-induced 1 and sulfur deficiency-induced 2 (SDI1 and SDI2) are involved in partitioning sulfur among metabolite pools during sulfur deficiency and their transcription is strongly induced by this condition. However, little is currently known about the cis- and trans-factors that regulate SDI expression. To identify potential transcription factors and DNA sequence element regulators of SDI expression we performed a comparative in silico analysis of their promoter sequences cataloguing known and potentially new cis-elements. We further screened an arrayed library of Arabidopsis transcription factors (TF) for binding to the SDI1 and SDI2 promoters. In total 14 candidate TF regulators of SDIs were identified with yeast-one-hybrid analyses, of which five bound to both promoters, 4 were specific to SDI1, and 5 were specific SDI2. Direct association between particular cis-elements in these promoter regions and specific TFs was established via electrophoretic mobility shift assays. SLIM1 was shown to bind SURE cis-element(s) in the proximal promoter region of both SDI1 and SDI2. The bZIP core cis-element in the proximal promoter region of SDI2 was shown to be important for bZIP16, bZIP44, and HYH binding. GBF1 was shown to bind the E-box in the proximal promoter region of SDI2. Additionally, we performed a meta-analysis of expression changes of these 14 TF candidates in a variety of conditions that alter SDI expression. These data will allow for more detailed future analysis of the molecular factors required for transcriptional regulation of SDIs under a range of physiological and metabolic conditions, apart from sulfur deficiency.

plant biology↗