The sweet potato B-box transcription factor gene IbBBX28 negatively regulates drought tolerance in transgenic Arabidopsis

Abstract

B-box (BBX) which are a class of zinc finger transcription factors, play an important role in regulating of photoperiod, photomorphogenesis, and biotic and abiotic stresses in plants. However, there are few studies on the involvement of BBX transcription factors in response to abiotic stresses in sweet potato. In this paper, we cloned the DNA and promoter sequences of IbBBX28. There was one B-box conserved domain in IbBBX28, and the expression of IbBBX28 was induced under drought stress. Under drought stress, compared to wild type Arabidopsis, the protective enzyme activities (SOD, POD, and CAT) were all decreased in IbBBX28-overexpression Arabidopsis but increased in the mutant line bbx28, while the MDA content was increased in the IbBBX28-overexpression Arabidopsis and decreased in the bbx28. Moreover, the expression levels of the resistance-related genes showed the same trend as the protective enzyme activities. These results showed that IbBBX28 negatively regulates drought tolerance in transgenic Arabidopsis. Additionally, the yeast two-hybrid and BiFC assays verified that IbBBX28 interacted with IbHOX11 and IbZMAT2. The above results provide important clues for further studies on the role of IbBBX28 in regulating the stress response in sweet potato.

Haplotype-Resolution Transcriptome Analysis Reveals Important Responsive Gene Modules and Allele-Specific Expression Contributions under Continuous Salt and Drought in Camellia sinensis

“…The WRKY55 and WRKY50 genes were reported to be induced in soybean plants under drought stress [55], and the former can positively regulate leaf senescence and the defense response through ROS and salicylic acid (SA)-related pathways in Arabidopsis [56]. In addition to drought stress, the homeobox-leucine zipper protein HOX11 has been reported to be involved in a variety of abiotic stress responses [57,58]. Thus, these transcript factors possibly play a key role in C. sinensis' response to early drought stress.…”

A B-Box Transcription Factor CoBBX24 from Camellia oleifera Delays Leaf Senescence and Enhances Drought Tolerance in Arabidopsis

“…BBX proteins are key regulators of plant growth and developmental processes, involved in seedling morphogenesis, the photoperiodic regulation of flower formation, shading response, anthocyanin accumulation, and responses to biological and abiotic stresses [7,[26][27][28][29]. Several BBX transcription factors play critical roles in the drought stress response of plants [30,31]. The rice BBX gene, Ghd2, confers drought sensitivity by upregulating senescence-associated genes (SAGs) in transgenic lines [32].…”

“…The rice BBX gene, Ghd2, confers drought sensitivity by upregulating senescence-associated genes (SAGs) in transgenic lines [32]. The heterologous expression of sweet potato IbBBX28 in Arabidopsis decreases the activities of the antioxidant enzymes, such as superoxide dismutase, peroxidase, and catalase, in IbBBX28-OX lines, indicating that IbBBX28 negatively regulates drought tolerance [30]. CmBBX22 mediates the ABA response to regulate the drought tolerance in chrysanthemum [33].…”