Sorghum (Sorghum bicolor L. Moench) is the world's fifth most‐produced cereal. The wall‐associated kinases (WAKs) gene family plays a crucial regulatory role in various aspects of plant biology, including the response to environmental stress and pathogens. Therefore, we aimed to characterize the members of the WAK gene family in sorghum using bioinformatics tools and to determine their functional roles in heat stress by detecting transcript levels using RT‐qPCR. A total of 98 SbWAK/SbWAKL proteins were identified and classified into six phylogenetic groups. The SbWAKs/SbWAKL genes were unevenly distributed across ten chromosomes, and 33 duplications were observed on nine chromosomes. The number of amino acids and molecular weight of SbWAKs/SbWAKLs ranged from 496 to 1149 aa and 55.38 to 124.89 kDa, respectively. Forty‐eight SbWAK/SbWAKL were unstable, with an instability index greater than 40. The synteny analyses revealed sixteen SbWAK/SbWAKL genes similar in foxtail millet, thirteen in maize, and seven in the rice genome. Additionally, 107 miRNAs, including cell wall‐related miRNAs, targeted 85 SbWAK/SbWAKL genes. The cis‐acting elements in SbWAK/SbWAKL genes pointed out that these genes may be associated with light, hormone, development, and environmental stress responses. RT‐qPCR analysis of 13 SbWAK/SbWAKL genes revealed a relatively high transcript fold change in 6 SbWAK/SbWAKL under high‐temperature conditions. In conclusion, cis‐acting elements, protein–protein and miRNA interactions, and higher gene expression levels at high temperatures may indicate the existence of candidate SbWAKs/SbWAKLs genes with functions in abiotic and biotic stress response and their usage in future gene editing for breeding purposes.

Wall-associated kinases (WAKs) are receptors that bind pectin or small pectic fragments in the cell wall and play roles in cell elongation and pathogen response. In the Cannabis sativa (Cs) genome, 53 CsWAK/CsWAKL (WAK-like) protein family members were identified and characterized; their amino acid lengths and molecular weights varied from 582 to 983, and from 65.6 to 108.8 kDa, respectively. They were classified into four main groups by a phylogenetic tree. Out of the 53 identified CsWAK/CsWAKL genes, 23 CsWAK/CsWAKL genes were unevenly distributed among six chromosomes. Two pairs of genes on chromosomes 4 and 7 have undergone duplication. The number of introns and exons among CsWAK/CsWAKL genes ranged from 1 to 6 and from 2 to 7, respectively. The promoter regions of 23 CsWAKs/CsWAKLs possessed diverse cis-regulatory elements that are involved in light, development, environmental stress, and hormone responsiveness. The expression profiles indicated that our candidate genes (CsWAK1, CsWAK4, CsWAK7, CsWAKL1, and CsWAKL7) are expressed in leaf tissue. These genes exhibit different expression patterns than their homologs in other plant species. These initial findings are useful resources for further research work on the potential roles of CsWAK/CsWAKL in cellular signalling during development, environmental stress conditions, and hormone treatments.

The annexin family is found in animals and plants and responds to a wide range of environmental stressors. In this study, 19 annexin proteins were identified based on their putative annexin repeats in Sorghum bicolor and further grouped on a phylogenic tree. These genes were randomly distributed across seven chromosomes. The amino acid length of sorghum annexins (SbAnn) varied from 241 (SbAnn3) to 370 (SbAnn2). Additionally, selective pressure analysis suggests the role of purification selection in conserving the annexin gene family in sorghum. Most SbAnns were located in the nucleus, cytoplasm, chloroplast, and mitochondrion. Also, higher syntenic relationships were observed between S. bicolor and monocots (S. italica, Z. mays, and O. sativa) than in A. thaliana. Cis-acting elements in the SbAnns gene promoters were grouped into response to light, hormone and environmental stress, and development-related elements. A number of miRNAs related to abiotic stress response targeted eleven SbAnns. Furthermore, five (SbAnn 4, 5, 14, 15, and 18) of the seven SbAnn genes utilized had relatively higher fold change under high-temperature treatment. This research provides insights into the characterization and functions of annexins under high temperatures.