Lesion mimic mutants (LMMs) form hypersensitive response (HR)-like lesions, a form of programmed cell death (PCD), in the absence of pathogens, that often confer durable and broad-spectrum disease resistance, representing a potential source for breeding resistance. However, most LMM plants have significant growth retardation including cell death, leaf senescence, damaged chloroplast structure, decreased chlorophyll contents, and undesirable agronomic traits. Therefore, LMMs represent ideal genetic materials to decipher interactions between defense signaling and programmed cell death, and growth. Many LMMs have been identified in rice, and at least 61 genes have been cloned and functionally confirmed. LMM genes are reported to participate in various regulation pathways, including gene transcription and protein translation, ubiquitin–proteasome pathway, protein phosphorylation, vesicle trafficking, metabolic pathways, and phytohormone signaling, highlighting the complexity of regulatory mechanisms. This review discusses recent progress on characteristics of rice LMM and mechanisms of LMM gene regulation, and suggests directions for future theoretical research and the potential use of LMMs in rice breeding.

Introduction: Wall-associated receptor kinases (WAKs) are a family of receptor-like kinases (RLKs) that play important roles in the communication between the plant cell wall and the cytoplasm. WAKs have been identified in several plants. However, a comprehensive investigation of maize WAKs has not been performed yet.Methods: In this study, the maize WAK gene family was identified through whole-genome scanning. y -30The physicochemical characteristics, chromosomal locations, phylogenetic tree, gene structures, conserved motifs, gene duplication, collinearity, and cis-acting elements of maize WAKs were analyzed.Results: A total of 56 ZmWAKs were identified in the maize genome and divided into seven subgroups. Among these, 54 genes were successfully mapped to maize chromosomes. Gene duplication events were detected in 13 ZmWAKs, with nine segmental (SD) and two tandem duplication (TD) events. Maize WAKs exhibited zero, eight, 27, and 41 collinear links with the WAKs from Arabidopsis, soybean, rice, and sorghum, respectively. In the promoter regions of ZmWAKs, a total of 107 types of cis-acting elements were predicted. Among them, the functions of 82 elements are known. These elements are associated with plant growth and development and light, hormones, stress, and defense responses. The transcriptome data analysis showed that ZmWAKs displayed tissue-specific expression and are involved in the responses to various abiotic and biotic stresses, including cold, salt, drought, waterlogging, pathogens, and pests. ZmWAK9, ZmWAK15, ZmWAK27, ZmWAK41, and ZmWAK49 are significantly induced by multiple stress conditions, indicating their crucial roles in stress responses and potential value for further research.Discussion: Our results provide insights into the function of maize WAKs in response to abiotic and biotic stresses and offer a theoretical foundation for understanding their mechanisms of action.

Flowering in plants is pivotal for initiating and advancing reproductive processes, impacting regional adaptation and crop yield. Despite numerous cloned and identified flowering time genes, research in cotton remains sparse. This study identified GhSWEET42 as a key determinant of the flowering time in cotton, demonstrating that its heterologous expression in Arabidopsis accelerated flowering under LD conditions compared to WT. Transgenic plants exhibited upregulated expression of the flowering inducers AtFT, AtSOC1, AtGI, and AtFKF1, alongside downregulated expression of the repressors AtTSF, AtFLC, and AtRGL2, correlating with the earlier flowering phenotype. GhSWEET42 showed a constitutive expression pattern, with elevated levels in the leaves, petals, and flower buds, and was notably higher in early-maturing cotton varieties. Subcellular localization assays confirmed GhSWEET42’s presence on the cell membrane. Transcriptome analysis between WT and GhSWEET42-overexpressing Arabidopsis plants revealed 2393 differentially expressed genes (DEGs), spanning 221 biological processes, 93 molecular functions, and 37 cellular components according to Gene Ontology (GO) enrichment analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis categorized the DEGs into metabolism and environmental information processing. These findings enhance the understanding of GhSWEET42’s function and provide a foundation for elucidating the molecular mechanisms governing flowering time regulation in cotton.

Northern corn leaf blight (NCLB) is a leaf disease caused by Setosphaeria turcica that infects maize at multiple growth stages and severely impairs photosynthesis and grain yield. Breeding for resistance to NCLB would be an effective strategy to mitigate the damage caused by this disease. Mapping of resistance genes provides an opportunity to understand the resistance mechanisms and to utilize the information in developing an introgression breeding strategy. The resistance of 421 maize inbred lines with extensive genetic variation to NCLB was evaluated over three consecutive years in Xinzhou, Shanxi. The proportions of maize lines classified as highly resistant, resistant, moderately resistant, susceptible, and highly susceptible were 1.06, 7.16, 20.16, 37.13, and 34.48%, respectively. A total of 39,676 high-quality SNP markers were employed for genome-wide association study (GWAS). In the early and late stages, 85 SNPs associated with NCLB resistance were identified, of which 11 stable SNPs were detected across the two environments. Through comparative transcriptome analysis, 4,758 and 3,779 differentially expressed genes (DEGs) were identified in the resistant inbred line Jing724 and the susceptible inbred line PH4CV after infection with S. turcica, respectively. GO and KEGG analyses indicated that more DEGs were enriched in plant defense pathways in the resistant line. Furthermore, two candidate genes were identified by integrating GWAS and transcriptome analyses. These findings could provide a foundation for cloning resistance genes and breeding resistant varieties.