Jasmonate activates a SlJAZ2/3‐SlMYC3‐like module regulating K+ uptake in tomato response to low K+ stress

ABSTRACT Potassium (K + ), an essential macronutrient, strongly influences myriad fundamental processes, while its deficiency inhibits plant growth. Jasmonic acid (JA) regulates plant growth; however, its role in plant growth inhibition under K + deficiency remains nebulous. Herein, we determined that JA significantly inhibits low K + tolerance and K + uptake in tomato. Methyl jasmonate treatment induced the expression of SlMYC3‐like under low K + stress, which bound the promoters of the genes that encode KT/KUP/HAK‐type transporter ( SlHAK5 ) and voltage‐gated K + channel ( SlLKT1 ) and inhibited their expression. Knockdown of SlMYC3‐like enhanced low K + stress tolerance and decreased JA responses, while its overexpression led to low K + stress sensitivity and promoted jasmonate responses in tomato. In addition, jasmonate ZIM‐domain transcriptional repressor 2/3 (SlJAZ2/3) interacted with SlMYC3‐like; this interaction decreased DNA‐binding activity of SlMYC3‐like. SlMYC3‐like promoted SlJAZ2 / 3 expression, forming a negative feedback circuit in JA signaling. Silencing SlJAZ2/3 increased plant susceptibility to low K + stress. Our findings demonstrate the involvement of the JA–SlJAZ2/3–SlMYC3‐like module in K + uptake and plant growth in tomato under low K + stress, providing novel insights into the regulation of plant growth and K + uptake.