Genome‑wide analysis of the maize LACSgene family and functional characterization of the ZmLACS9responses to heat stress

•The LACSs complement of maize were identified and systematically characterized through phylogenetic, structural, and expression analyses.•ZmLACS9loss-of-expression mutation resulted in decreased chlorophyll content and fewer thylakoid grana layers compared to the wild type.•Under heat stress, the zmlacs9mutant exhibited a more sensitive phenotype, more damage to chloroplasts, lower photosynthetic rate, and higher reactive oxygen species accumulation than WT plants.