Transcriptome and weighted gene co-enrichment analysis revealed modules and candidate genes associated with barley response to low potassium stress

Kexian Zhang¹Bingjie Chen²Jian Ma³Qing Lai¹Deyi Hu¹Yuanfeng Huo¹Zhaoyong Zeng¹Yinggang Xu¹Yuanjie Song¹Jian Zeng¹Zhongwei Zhang¹Haihua Xiao¹Shu Yuan^1*Guangdeng Chen^1*

• ¹College of Resources, Sichuan Agricultural University, Chengdu, China
• ²Northwest A&F University College of Natural Resources and Environment, Yangling, China
• ³Triticeae Research Institute, Sichuan Agricultural University, Chengdu, China

Potassium deficiency is one of the key factors affecting crop yields. This study investigated the effects of low potassium stress on the growth of three barley varieties from physiological and biochemical indicators, transcriptomicsand weighted gene co-enrichment analysis. Results indicate that low potassium treatment reduced potassium accumulation, plant height, root surface area, dry weight, and photosynthetic parameters in all barley varieties, thereby inhibiting barley growth. Significantly enhanced potassium transport coefficients in stems, along with increased H+,K+-ATPase activities, indicate that this enzyme play a crucial role in alleviating potassium deficiency stress in barley. Transcriptome analysis indicates that low potassium treatment primarily affects hormone signal synthesis and transduction, antioxidant enzymes, and transcription factors. Differentially expressed genes are mainly involved in plant defense and immunity, metabolite and energy regulation, photosynthesis, carbohydrate and nitrogen metabolism, as well as hormone and developmental regulation. Through WGCNA analysis, 12 pivotal genes exhibiting strong interactions were identified in root-MEbrown, stem-MEpink, and stem-MEturquoise. Five genes (LOC123407914, LOC123448799, tplb0006k10, NIASHv2043B04, NIASHv3101N17) belong to the same KEGG pathway: ko03040 (Splicosome), classified under the primary pathway category of Cellular Processes. These 12 genes maintain apical meristem activity and H+-K+-ATPase activity, regulate photosynthetic efficiency, maintain leaf width, ensure energy synthesis and function at the RNA helicase and nucleolar levels within the nucleus to ensure normal plant growth under low-potassium stress. Moreover, three of these genes may undergo alternative splicing events, and the effects of potassium deficiency on alternative splicing have been rarely reported. Further research on these genes may fill this gap.