HvbZIP21, a Novel Transcription Factor From Wild Barley Confers Drought Tolerance by Modulating ROS Scavenging

Abstract

Drought stress is a common environmental stress, which adversely affects the yield and quality of crops. Due to its excellent drought tolerance, wild barley from the Middle East region is considered a valuable source for barley improvement. Here, we compared the growth rate, stomatal regulation and capacity to metabolize reactive oxygen species (ROS) of two barley cultivars and one wild barley accession. The results indicated the wild barley EC_S1 showed a more significant decline in stomatal aperture and less ROS production. Transcriptomic analysis revealed that EC_S1 has slower transcriptional regulation (5,050 DEGs) in the early stage of drought stress (14 days) than Baudin (7,022 DEGs) and Tadmor (6,090 DEGs). In addition, 30 hub genes, including nine known drought-related genes were identified by WGCNA analysis. Then, we cloned a novel bZIP transcription factor, HvbZIP21, from EC_S1. HvbZIP21 was subcellularly targeted to the nucleus. Overexpression of HvbZIP21 in Arabidopsis enhanced drought tolerance due to increasing activities of superoxide dismutase, peroxidase, and catalase activities as well as glutathione content. Silencing of HvbZIP21 in EC_S1 suppressed drought tolerance in BSMV:HvbZIP21-inoculated plants. Taken together, our findings suggest that HvbZIP21 play a critical role in drought tolerance by manipulating ROS scavenging.

Efficient Gene Editing and Overexpression of Gametophyte Transformation in a Model Fern

“…The pictures were imported into the ImageJ software for the analysis of multiple parameters. Stomatal area (total stomatal area), stomatal perimeter (total length of the stomatal outer border), stomatal length (top to bottom of the stomatal), stomatal width (left to right of the stomatal), pore area (total pore area), pore perimeter (total length of the pore outer border), pore length (top to bottom of the pore), and pore width (left to right of the pore) were recorded (Pan et al, 2022). There were 20–30 stomata with three biological replicates for each treatment and genotype.…”

Genome editing to re-domesticate and accelerate use of barley crop wild relatives

“…Research in wild barley has identified some of the genetic basis of salinity and drought tolerance (Ebrahim et al, 2020;Khalil et al, 2021). Wild barley accessions from arid regions seem to be superior under drought stress (Hong et al, 2020;Pan et al, 2022;Wang et al, 2023). Transcriptome analysis of wild barley led to the discovery of several differentially expressed genes that are responsible for gas exchange and stomatal traits (Ashoub et al, 2018;Chen et al, 2019).…”

“…Wu et al (2022) found a wild barley polymorphis for increased β-amylase activity during drought stress in wild barley. While Shrestha et al (2022) identified a new polymorphism in the proline accumulation pathway and Pan et al (2022) found a polymorphism in the ROS scavenging pathway, both conferring increased drought stress. Nitrogen use efficiency (NUE) is increasingly important (Ekardt et al, 2018).…”

Grapevine bZIP transcription factor bZIP45 regulates VvANN1 and confers drought tolerance in Arabidopsis

“…The wilting degree was noticeably lower in TabZIP15 overexpressing plants than in KN199 plants under salt treatment ( Bi et al., 2021 ). HvbZIP21 play a key role in drought stress tolerance through modulating ROS scavenging ( Pan et al., 2022 ). The bZIP TFs can bind to the core sequence (-ACGT-) in the promoter of downstream genes (e.g., the G-box, C-box, and A-box), thereby participating in the transcriptional regulation of plant responses to stress ( Nijhawan et al., 2008 ).…”