Study on the Function of SlWRKY80 in Tomato Defense against Meloidogyne incognita

WRKY transcription factors (TFs) can participate in plant biological stress responses and play important roles. <i>SlWRKY80</i> was found to be differentially expressed in the <i>Mi-1</i>- and <i>Mi-3</i>-resistant tomato lines by RNA-seq and may serve as a key node for disease resistance regulation. This study used RNAi to determine whether <i>SlWRKY80</i> silencing could influence the sensitivity of 'M82' (<i>mi-1</i>/<i>mi-1</i>)-susceptible lines to <i>M. incognita</i>. Further overexpression of this gene revealed a significant increase in tomato disease resistance, ranging from highly susceptible to susceptible, combined with the identification of growth (plant height, stem diameter, and leaf area) and physiological (soluble sugars and proteins; root activity) indicators, clarifying the role of <i>SlWRKY80</i> as a positive regulatory factor in tomato defense against <i>M. incognita</i>. Based on this phenomenon, a preliminary exploration of its metabolic signals revealed that <i>SlWRKY80</i> stimulates different degrees of signaling, such as salicylic acid (SA), jasmonic acid (JA), and ethylene (ETH), and may synergistically regulate reactive oxygen species (ROS) accumulation and scavenging enzyme activity, hindering the formation of feeding sites and ultimately leading to the reduction of root gall growth. To our knowledge, <i>SlWRKY80</i> has an extremely high utilization value for improving tomato resistance to root-knot nematodes and breeding.