Extensive genome structure variation, such as copy number variations (CNVs) and presence/absence variations, is the basis for the remarkable maize genetic diversity; however, the effect of CNVs on maize herbivory defense remains largely underexplored. Here, we report that the naturally occurring duplication of the maize 9-lipoxygenase gene, ZmLOX5, leads to increased resistance of maize to herbivory by fall armyworms (FAW). Previously, we showed that ZmLOX5-derived oxylipins are required for defense against chewing insect herbivores and identified several inbred lines, including Yu796, that contained duplicated CNVs of ZmLOX5, referred to as Yu796-2×LOX5. To test whether introgression of the Yu796-2×LOX5 locus into the herbivore-susceptible B73 background that contains a single ZmLOX5 gene is a feasible approach to increase resistance, we generated a series of near-isogenic lines that contained either 2, 1 or 0 copies of the Yu796-2×LOX5 locus in the B73 background by six back crosses (BC6). Droplet digital PCR (ddPCR) confirmed the successful introgression of the Yu796-2×LOX5 locus in B73. The resulting B73-2×LOX5 inbred line displayed increased resistance against FAW associated with increased expression of ZmLOX5, increased wound-induced production of its primary oxylipin product, the α-ketol, 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid (9,10-KODA), and the downstream defense hormones regulated by this molecule, 12-oxo-phytodienoic acid (12-OPDA) and abscisic acid (ABA). Surprisingly, wound-induced JA-Ile production was not increased in B73-2×LOX5, resulting from the increased JA catabolism. Furthermore, B73-2×LOX5 displayed enhanced drought tolerance likely due to increased ABA and 12-OPDA content. Taken together, this study revealed that the duplicated CNV of ZmLOX5 quantitively contributes to maize antiherbivore defense and presents proof-of-concept evidence that the introgression of naturally occurring duplicated CNVs of a defensive gene into the productive, but susceptible, crop varieties is a feasible breeding approach for enhancing plant resistance to herbivory and tolerance to abiotic stress.

COVID-19 sepsis immune response remains unclear. Here we propose a new perspective in host response against pathogenic proteins that may lead to a vaccine design by polymerization of antigens of <70 kDa. In COVID-19, initial Th1 response kills infected cells releasing viral proteins. SARS-CoV-2 viral structural proteins are Spike (140 kDa), Nucleocapsid (50 kDa), Membrane (25 kDa) and Envelope (10 kDa). B cell receptor cannot capture antigens >70 kDa. The Spike protein (140 kDa) cannot be captured by B cells and triggers inflammatory Th1 response via the macrophages. Only proteins with a size <70 kDa can activate B cell receptor and trigger Th2 adaptative humoral response. Moreover, M-25 kDa and E-12 kDa glycoproteins can activate IgM-BCR like oligovalent or monovalent antigens. The sustained infected cells lysis overfeeds high levels of viral proteins <70 kDa, increases B cells activation and, in the shift from Th1 to Th2 immune response, triggers the cytokine storm. The continuous BCR activation increases IL-10 releasing and may lead to immune paralysis.