Genome-wide analysis of the Amorphophallus konjac AkCSLA gene family and its functional characterization in drought tolerance of transgenic arabidopsis

Background: Amorphophallus konjac (A. konjac), a perennial tuberous plant, is widely cultivated for its high konjac glucomannan (KGM) content, a heteropolysaccharide with diverse applications. The cellulose synthase-like (CSL) gene family is known to be a group of processive glycan synthases involved in the synthesis of cell-wall polysaccharides and plays an important role in the biological process of KGM. However, in A. konjac the classification, structure, and function of the AkCSLA superfamily have been studied very little.

Results: Bioinformatics methods were used to identify the 11 AkCSLA genes from the whole genome of Amorphophallus konjac and to systematically analyze their characteristics, phylogenetic evolution, promoter cis-elements, expression patterns, and subcellular locations. Phylogenetic analysis revealed that the AkCSLA gene family can be divided into three subfamilies (Groups I- III), which have close relationships with Arabidopsis. The promoters of most AkCSLA family members contain MBS elements and ABA response elements. Analysis of expression patterns in different tissues showed that most AkCSLAs are highly expressed in the corms. Notably, PEG6000 induced down-regulation of the expression of most AkCSLAs, including AkCSLA11. Subcellular localization results showed that AkCSLA11 was localized to the plasma membrane, Golgi apparatus and endoplasmic reticulum. Transgenic Arabidopsis experiments demonstrated that overexpression of AkCSLA11 reduced the plant's drought tolerance. This overexpression also inhibited the expression of drought response genes and altered the sugar components of the cell wall. These findings provide new insights into the response mechanisms of A. konjac to drought stress and may offer potential genetic resources for improving crop drought resistance.

Conclusion: In conclusion, the study reveals that the AkCSLA11 gene from A. konjac negatively impacts drought tolerance when overexpressed in Arabidopsis. This discovery provides valuable insights into the mechanisms of plant response to drought stress and may guide future research on crop improvement for enhanced resilience.