Shenghua Xiao, Yang Wu, Shiqiang Xu, Hongtao Jiang, Qin Hu, Wei Yao and Muqing Zhang

Front. Plant Sci., 01 November 2022
Sec. Plant Biotechnology; https://doi.org/10.3389/fpls.2022.963377

Sugarcane is one of the most crucial sugar crops globally that supplies the main raw material for sugar and ethanol production, but drought stress causes a severe decline in sugarcane yield worldwide. Enhancing sugarcane drought resistance and reducing yield and quality losses is an ongoing challenge in sugarcane genetic improvement. Here, we introduced a Tripidium arundinaceum dehydration-responsive element-binding transcription factor (TaDREB2B) behind the drought-responsible RD29A promoter into a commercial sugarcane cultivar FN95-1702 and subsequently conducted a series of drought tolerance experiments and investigation of agronomic and quality traits. Physiological analysis indicated that Prd29A: TaDREB2B transgenic sugarcane significantly confers drought tolerance in both the greenhouses and the field by enhancing water retention capacity and reducing membrane damage without compromising growth. These transgenic plants exhibit obvious improvements in yield performance and various physiological traits under the limited-irrigation condition in the field, such as increasing 41.9% yield and 44.4% the number of ratooning sugarcane seedlings. Moreover, Prd29A: TaDREB2B transgenic plants do not penalize major quality traits, including sucrose content, gravity purity, Brix, etc. Collectively, our results demonstrated that the Prd29A-TaDREB2B promoter-transgene combination will be a useful biotechnological tool for the increase of drought tolerance and the minimum of yield losses in sugarcane.

See https://www.frontiersin.org/articles/10.3389/fpls.2022.963377/full

FIGURE 1:  Phylogenetic tree and amino acid sequence alignment of TaDREB2B. (A) Phylogenetic analysis of TaDREB2B and other AP2/ERF transcription factors from Arabidopsis, rice, and maize. The red triangle represents the TaDREB2B protein. (B) Alignment of TaDREB2B, AtDREB2A, AtDREB2B, AtERF4 and AtERF10 protein sequences. The red rectangle represents the AP2 domain, and the purple rectangles show the amino acid on the 14th and 19th.