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The fall armyworm (FAW) poses a significant threat to global crop production. Here we showed that overexpression of jasmonate ZIM-domain (JAZ) protein GhJAZ24 confers resistance to cotton bollworm and FAW, while also causing sterility in transgenic cotton by recruiting TOPLESS and histone deacetylase 6. We identified the NGR motif of GhJAZ24 that recognizes and binds the aminopeptidase N receptor, enabling GhJAZ24 to enter cells and disrupt histone deacetylase 3, leading to cell death. To overcome plant sterility associated with GhJAZ24overexpression, we developed iJAZ (i, induced), an approach involving damage-induced expression and a switch from intracellular to extracellular localization of GhJAZ24. iJAZ transgenic cotton maintained fertility and showed insecticidal activity against cotton bollworm and FAW. In addition, iJAZ transgenic rice, maize and tobacco plants showed insecticidal activity against their lepidopteran pests, resulting in an iJAZ-based approach for generating alternative insecticidal proteins with distinctive mechanisms of action, thus holding immense potential for future crop engineering.

Pathogenic oomycetes infect a wide variety of organisms, including plants, animals, and humans, and cause massive economic losses in global agriculture, aquaculture, and human health. Salicylic acid (SA), an endogenous phytohormone, is regarded as an inducer of plant immunity. Here, the potato late blight pathogen Phytophthora infestanswas used as a model system to uncover the inhibitory mechanisms of SA on pathogenic oomycetes. In this research, SA significantly inhibited the mycelial growth, sporulation, sporangium germination, and virulence of P. infestans. Inhibition was closely related to enhanced autophagy, suppression of translation initiation, and ribosomal biogenesis in P. infestans, as shown by multiomics analysis (transcriptomics, proteomics, and phosphorylated proteomics). Monodansylcadaverine (MDC) staining and Western blotting analysis showed that SA promoted autophagy in P. infestansby probably targeting the TOR signaling pathway. These observations suggest that SA has the potential to control late blight caused by P. infestans.

Using chemical fungicides is the main strategy for controlling potato late blight (PLB), a devastating pre- and postharvest disease caused by Phytophthora infestans, resulting in environmental pollution and health risks. It is of great importance to develop a biofungicide from microorganisms. Through isolating potato rhizosphere microorganisms, CQUSh011 was found to have antioomycete activity with strong inhibition on vegetative growth and virulence of P. infestans. Morphological and molecular identification indicated that CQUSh011 belongs to Streptomyces rapamycinicus. Based on genome, metabolome, and HPLC quantification, rapamycin and salicylic acid were found to be the two active metabolites against P. infestans. Continuous field trials showed that CQUSh011 has sustainable control efficiency against PLB, and the efficiency was better when combined with Infinito, along with an increased endophytic microbial community and biodiversity in potato roots. The results demonstrated the potential of CQUSh011 as a biofungicide against PLB and provided an alternative strategy for reducing the application of chemical fungicides.