ABP9, a maize bZIP transcription factor, enhances tolerance to salt and drought in transgenic cotton

Abstract

ABP9 , encoding a bZIP transcription factor from maize, enhances tolerance to multiple stresses and may participate in the ABA signaling pathway in transgenic cotton by altering physiological and biochemical processes and stress-related gene expression. Abiotic stresses, such as soil salinity and drought, negatively affect growth, development, and yield in cotton. Gene ABP9, which encodes a bZIP transcription factor, binds to the abscisic acid (ABA)-responsive-element (ABRE2) motif of the maize catalase1 gene. Its expression significantly improves tolerance in Arabidopsis to multiple abiotic stresses, but little is known about its role in cotton. In the present study, the ABP9 gene was introduced into upland cotton (Gossypium hirsutum L.) cultivar R15 by Agrobacterium tumefaciens-mediated transformation, and 12 independent transgenic cotton lines were obtained. Cotton plants over-expressing ABP9 have enhanced tolerance to salt and osmotic stress. Under stress, they developed better root systems in a greenhouse and higher germination, reduced stomatal aperture, and stomatal density in a growth chamber. Under drought conditions, survival rate and relative water content (RWC) of transgenic cotton were higher than those of R15 plants. Under salt and osmotic stresses, chlorophyll, proline, and soluble sugar contents significantly increased in transgenic cotton leaves and the malondialdehyde (MDA) content was lower than in R15. Overexpression of ABP9 also enhanced oxidative stress tolerance, reduced cellular levels of reactive oxygen species (ROS) through increased activities of antioxidative enzymes, and alleviated oxidative damage to cell. Interestingly, ABP9 over-expressing cotton was more sensitive to exogenous ABA than R15 at seed germination, root growth, stomatal aperture, and stomatal density. Moreover, ABP9 overexpression upregulated significantly the transcription levels of stress-related genes such as GhDBP2, GhNCED2, GhZFP1, GhERF1, GhHB1, and GhSAP1 under salt treatment. Conjointly, these results showed that overexpression of ABP9 conferred enhanced tolerance to multiple abiotic stresses in cotton. The stress-tolerant transgenic lines provide valuable resources for cotton breeding.

Tartary Buckwheat Transcription Factor FtbZIP5, Regulated by FtSnRK2.6, Can Improve Salt/Drought Resistance in Transgenic Arabidopsis

“…Both MDA and proline are main indicators for determining plant stress resistance. Previous studies have shown that AREB/ABFs, such as ABP9 and VvABF1, can increase antioxidant enzyme activity and proline content, and reduce ROS accumulation and MDA content to improve the resistance of transgenic plants [38,39]. As expected, our experimental results also show that FtbZIP5 has functions similar to those of these AREB/ABFs.…”

The involvement of wheat U‐box E3 ubiquitin ligase TaPUB1 in salt stress tolerance

“…Soluble sugars contribute to osmotic adjustments and the regulation of ROS signaling, and the synthesis of soluble sugars is a critical process under salt stress (Chen et al 2005; Seki et al 2007; Wang et al 2015c). Proline serves as an osmoprotectant when plants are exposed to salt stress (Bartels and Sunkar 2005; Wang et al 2017). In this study, TaPUB1 could enhance the levels of proline and soluble sugars in plants during salt stress (Figure E, F).…”

Overexpression of the caryophyllene synthase gene GhTPS1 in cotton negatively affects multiple pests while attracting parasitoids

“…The recombinant pCAMBIA2301-CaMV35S::GhTPS1 plasmid was inserted into the domesticated variety R15 plant (G. hirsutum cv. R15) using the methods by Wang et al 34 Briefly, the recombinant plasmid pCAMBIA2301-CaMV35S::GhTPS1 was transformed into Agrobacterium tumefaciens strain LBA4404 by electroporation. The hypocotyl segment of cotton seedlings infected by the positive strain was used to form embryogenic calluses.…”

“…The resulting transgenic plants were confirmed by PCR analysis for every plant generation. Transgenic overexpression lines L18 and L46 (representative T3 and T2 lines) were also grown as described by Wang et al 34 and used for all experiments at the 8-10 expanded true-leaf stage. H. armigera was reared in a climate-controlled room (27 ± 2 ∘ C, 75 ± 10% RH, 14:10 L:D regime).…”