Transcriptome analysis reveals the responsive pathways to potassium (K+) deficiency in the roots and shoots of grapevines

Abstract

Grapevine is sensitive to potassium (K+) deficiency, while its underlying responsive mechanisms are unknown. In this study, transcriptome profiling of grapevine seedlings under K+ deficiency conditions over a time course were investigated. Morphological measurements showed that K+ deficiency inhibited the normal growth of grapevine seedlings. RNA-sequencing (RNA-seq) was performed with samples of roots and shoots collected under K+ deficiency and normal conditions, and numerous differentially expressed genes (DEGs) induced by K+ deficiency were identified, including some ion transporter genes, ethylene-responsive transcription factor (ERF) genes, and cell wall biosynthesis-related genes. In roots, by functional and regulatory pathway analysis, genes in ethylene signal (especially ERF) and in cell wall biosynthesis pathway were upregulated and downregulated, respectively, indicating that ethylene signal was activated, while cell wall biosynthesis was inhibited under K+ deficiency treatment. And in shoots, genes in ethylene signal and in photosynthesis pathway were upregulated and downregulated, respectively, revealing that ethylene signal was activated, while photosynthesis was suppressed under K+ deficiency treatment. Analysis of transcription factors indicated that ERF family extensively involved in the response to K+ deficiency. Taken together, this study reveals the multiple molecular responses, including ethylene signal, ion homeostasis, and other metabolic pathways, to K+ deficiency treatment in grapevines.