Transcriptome and weighted gene co-enrichment analysis revealed modules and candidate genes associated with barley...

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, transcriptomics and 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 plays 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, shoot-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.