Genome-Wide Analysis of the β-Amylase Gene Family in Brassica L. Crops and Expression Profiles of BnaBAM Genes in Response to Abiotic Stresses

Abstract

The β-amylase (BAM) gene family, known for their property of catalytic ability to hydrolyze starch to maltose units, has been recognized to play critical roles in metabolism and gene regulation. To date, BAM genes have not been characterized in oil crops. In this study, the genome-wide survey revealed the identification of 30 BnaBAM genes in Brassica napus L. (B. napus L.), 11 BraBAM genes in Brassica rapa L. (B. rapa L.), and 20 BoBAM genes in Brassica oleracea L. (B. oleracea L.), which were divided into four subfamilies according to the sequence similarity and phylogenetic relationships. All the BAM genes identified in the allotetraploid genome of B. napus, as well as two parental-related species (B. rapa and B. oleracea), were analyzed for the gene structures, chromosomal distribution and collinearity. The sequence alignment of the core glucosyl-hydrolase domains was further applied, demonstrating six candidate β-amylase (BnaBAM1, BnaBAM3.1-3.4 and BnaBAM5) and 25 β-amylase-like proteins. The current results also showed that 30 BnaBAMs, 11 BraBAMs and 17 BoBAMs exhibited uneven distribution on chromosomes of Brassica L. crops. The similar structural compositions of BAM genes in the same subfamily suggested that they were relatively conserved. Abiotic stresses pose one of the significant constraints to plant growth and productivity worldwide. Thus, the responsiveness of BnaBAM genes under abiotic stresses was analyzed in B. napus. The expression patterns revealed a stress-responsive behaviour of all members, of which BnaBAM3s were more prominent. These differential expression patterns suggested an intricate regulation of BnaBAMs elicited by environmental stimuli. Altogether, the present study provides first insights into the BAM gene family of Brassica crops, which lays the foundation for investigating the roles of stress-responsive BnaBAM candidates in B. napus.

Genome-wide identification of BAM (β-amylase) gene family in jujube (Ziziphus jujuba Mill.) and expression in response to abiotic stress

“…This indicates that the duplicated genes might have diverged during evolution. Similar results were found in the syntenic relationships among the BAM genes of Arabidopsis and Brassica [ 38 ].…”

“…BAM is a multigene family in several different plant species. Nine BAM genes were identified in A. thaliana [ 18 ], four in rice [ 35 ], nine in barley [ 36 ], 16 in banana [ 37 ], six in grapevine [ 31 ], 30 in Brassica napus , 11 in B. rapa , and 20 in B. oleracea [ 38 ]. Here, we identified nine genes ( ZjBAM1 – ZjBAM9 ) encoding BAM in the jujube genome database.…”

“…For instance, AaBAM3.1 overexpression increases freezing tolerance in A. thaliana ; heterologous AaBAM3.1 overexpression yields consistent results [ 49 ]. Moreover, the expression of BnaBAM3 and BnaBAM5 is significantly upregulated in Brassica under heat stress [ 38 ]. Meanwhile, VvBAM1 overexpression in tomatoes alters the soluble sugar levels and improves cold tolerance [ 31 ].…”

Genome-wide characterization and expression analysis of α-amylase and β-amylase genes underlying drought tolerance in cassava

“…Metabolites of carbohydrates in plant leaves release soluble sugar, which can act as osmotic protecting agents, thus maintaining the water balance in cells enables plants to adapt to stress [13,[35][36][37]. During drought stress, the total enzyme activity of α-amylase and β-amylase increased in cassava leaves and stems, leading to higher soluble sugar and lower starch contents of cassava roots, stems, and leaves than those of the CK (Fig.…”

Elevated CO2 and temperature under future climate change increase severity of rice sheath blight

“…Secondly, the starch of stems was determined by acid hydrolysis method using the kit (G0507W, Suzhou Grace Bio-technology Co., LTD, Suzhou, China) ( Luo et al., 2020 ). The frozen samples of stems were grounded to powder in liquid nitrogen, and 0.1 g sample was added to 1 mL of 80% ethanol and extracted at 80 °C water bath for 30 minutes, the extraction buffer was centrifuged at 3000 rpm for 5 minutes at room temperature.…”