Search

Cotton is one of the most important cash crops in the world. Most of its production areas are in arid or semiarid regions, and drought and salinity seriously affect cotton production. Plant teosinte branched1/cycloidea/proliferating cell factor 1 (TCP) transcription factors play a pivotal role in abiotic stress responses. However, the role of TCPs in the abiotic stress response in cotton has not been fully elucidated. Here, the function of the GbTCP5 transcription factor in the responses to drought and salt stresses was identified. The expression of GbTCP5 was induced by drought, salt, and abscisic acid (ABA) treatments. The exposure of 35S: GbTCP5 transgenic Arabidopsis to drought stress increased its survival rate and ABA content and decreased its leaf water loss rate and malondialdehyde (MDA) content compared with those of the wild type (WT). In addition, the expression levels of the stress response genes AtCOR15 , AtCOR414 , AtRD29A , AtLTP4 , and AtPUB22 and the ABA biosynthesis-related gene AtNCED3 were significantly higher in 35S: GbTCP5 transgenic lines than in the WT. The exposure of 35S: GbTCP5 transgenic Arabidopsis to salt stress accelerated its germination rate, increased its root length, survival rate and chlorophyll content, and decreased the MDA content compared with those of the WT. Under drought or salt stress, cotton with virus-induced gene silencing of GbTCP5 showed a decreased survival rate, a shorter root length, a smaller root area, a reduced root volume and a higher MDA content compared with pTRV2 cotton. Transcriptome sequencing results confirmed that GbTCP5 was involved in several abiotic stress-related metabolic pathways. The results confirmed that GbTCP5 protein activated the expression of GbGLOS2 , GbUBC19 , and GbERD7 and then participated in the drought and salt tolerance of cotton by binding to the TCP cis -acting element in the promoter regions of these genes. All the above results prove that GbTCP5 plays a positive role in plant responses to drought and salt stress. [Display omitted] • The GbTCP5 gene was transcriptionally responsive to polyethylene glycol, NaCl, and abscisic acid treatments. • Overexpression of GbTCP5 in Arabidopsis and silencing of GbTCP5 in cotton indicate that GbTCP5 is a positive regulator of drought and salt stress. • RNA-seq analysis showed that pTRV2- GbTCP5 cotton plants had 489 differentially expressed genes compared with pTRV2 cotton plants, among which 234 were upregulated genes and 255 were downregulated genes. • GbTCP5 enhances drought and salt tolerance in plants by binding to TCP cis -acting elements in the GbERD 7/ GbUBC19 / GbGOLS2 promoter and activating their expression. [ABSTRACT FROM AUTHOR]

Abstract Drought is the most serious meteorological disaster affecting wheat production. Members of the R2R3-MYB gene subfamily play a crucial role in the regulation of the wheat drought stress response. In this study, the function of polyethylene glycol (PEG)-induced expression of the wheat R2R3-MYB gene TaSIM in response to drought stress was characterized. β-Glucuronidase (GUS) histochemical staining revealed that the TaSIM promoter can drive the expression of the GUS gene in the flowers, roots, stems and rosette leaves. Moreover, TaSIM was expressed in the stamens, pistils, roots, stems and leaves of wheat. The TaSIM promoter contains a known stress-responsive cis -acting element and is inducible by stress, PEG and abscisic acid (ABA). Under drought stress, compared with wild-type (WT) Arabidopsis , transgenic Arabidopsis overexpressing TaSIM presented significantly lower leaf water loss rates and increased survival. Moreover, the content of soluble sugars and proline and the expression of stress-related genes (RD29A and RD22) in transgenic Arabidopsis overexpressing TaSIM were higher than those in WT Arabidopsis under drought stress. Our results indicate that TaSIM plays a positive role in the drought stress response and can be used as a candidate gene for the genetic engineering of wheat drought resistance. Highlights • TaSIM is expressed in the stamens, pistils, roots, stems and leaves of wheat. • ABRE and CRT/DRE cis -acting elements are present in the TaSIM promoter, which is induced by stress, PEG and ABA. • Transgenic Arabidopsis overexpressing TaSIM has a low water loss rate, accumulates relatively high contents of soluble sugars and proline, and expresses RD22 and RD29A , thereby enhancing Arabidopsis tolerance to drought stress. [ABSTRACT FROM AUTHOR]

TCP transcription factors play important regulatory roles in plant growth and development; however, their function in response to salt and drought stress in sea-island cotton (Gossypium barbadense) is unknown. Here, GbTCP4 expression was induced by abscisic acid (ABA), drought, and NaCl treatments. Under drought stress, compared to wild-type (WT) Arabidopsis , transgenic GbTCP4 -overexpressing Arabidopsis showed increased seed germination rate, root length and survival rate; additionally, it was ABA-insensitive at the germination stage but ABA-sensitive at the seedling stage, showing reduced stomatal opening and ABA enrichment. Under salt stress, compared to WT Arabidopsis , transgenic GbTCP4- overexpressing Arabidopsis showed greater root length, survival rate, and SPAD value and lower malondialdehyde (MDA) content. Conversely, under drought or salt stress, virus-induced gene-silenced GbTCP4 cotton showed decreased root length, area and volume and increased MDA content and sensitivity to drought and salt stress compared with control cotton. RNA-seq and quantitative real-time PCR analyses showed that GbTCP4 affected the transcription levels of genes across multiple abiotic stress-related metabolic pathways. Furthermore, GbTCP4 activated the transcription of GbUVR8 and GbbHLH130 by binding to their promoters. These results suggest that GbTCP4 positively regulates drought and salt stress responses and is a suitable candidate gene for improving plant drought and salt tolerance. • The sea-island cotton class II TCP gene GbTCP4 is induced by drought, salt, and ABA treatments. • Overexpression of GbTCP4 in Arabidopsis and silencing of GbTCP4 in cotton indicated that GbTCP4 is a positive regulator of drought and salt stress. • GbTCP4 regulates abiotic stress responses in an ABA-dependent manner. • The GbTCP4 transcription factor can affect the expression of key genes in multiple stress-related metabolic pathways. [ABSTRACT FROM AUTHOR]

• The GmNF-YA10 gene encodes an NF-YA transcription factor located in the nucleus that responds to PEG and ABA treatment at the transcription level. • Overexpression of the GmNF-YA10 gene increases the drought resistance of transgenic Arabidopsis by accumulating osmotic substances, slowing membrane lipid peroxidation, enhancing photosynthesis, regulating ABA-mediated stomatal closure, reducing the leaf water loss rate, and affecting the transcript levels of stress-related genes. • GmNF-YA10 gene participates in Arabidopsis response to drought stress through two pathways, ABA-dependent and ABA-independent. Nuclear factor (NF)-Y is composed of three subunits, NF-YA, NF-YB and NF-YC, and plays important roles in the regulation of plant abiotic stress response gene expression. However, the function of individual soybean NF-YA proteins in response to drought stress is unclear. In this study, the soybean NF-YA subunit gene GmNF-YA10 was cloned, and its function in response to drought stress was identified. GmNF-YA10 is broadly expressed in soybean tissues and is specifically located in the nucleus. In soybean roots, the transcription level of the GmNF-YA10 gene was induced by polyethylene glycol (PEG)-simulated drought stress and abscisic acid (ABA) treatment. Under mannitol stress, the germination rate of transgenic Arabidopsis overexpressing GmNF-YA10 was higher than that of wild-type (WT) Arabidopsis. After drought stress, the survival rate, relative water content, ABA content, proline content and chlorophyll content of transgenic Arabidopsis overexpressing GmNF-YA10 were higher than those of WT Arabidopsis while the rate of water loss and the contents of malondialdehyde and sucrose were lower than those of WT Arabidopsis , indicating that transgenic Arabidopsis overexpressing GmNF-YA10 has better drought resistance than WT Arabidopsis. Under the ABA treatment, the root length of transgenic Arabidopsis overexpressing GmNF-YA10 was shorter than that of WT Arabidopsis and the degree of stomatal closure was greater than that of WT Arabidopsis , indicating that transgenic Arabidopsis overexpressing GmNF-YA10 was more sensitive to ABA at the post-germination stage. Transcriptome sequencing and real-time quantitative PCR analysis showed that GmNF-YA10 affected the expression of both ABA-dependent and ABA-independent signalling pathway genes. These results indicate that GmNF-YA10 significantly improves the drought resistance of transgenic Arabidopsis through ABA-dependent and ABA-independent signal transduction pathways. [ABSTRACT FROM AUTHOR]

• GmFBX176 encodes a nuclear-localized F-box protein that responds to PEG treatment, ABA treatment, and salt stress at the transcriptional level. • Stress tolerance analysis of heterologous GmFBX176-overexpressing Arabidopsis revealed that GmFBX176 is a negative regulatory protein that improves tolerance to drought and salt stress. • GmFBX176-overexpressing Arabidopsis displayed reduced sensitivity to ABA. • Constitutive heterologous overexpression of the GmFBX176 gene affects stress-related physiological indicators and the transcript levels of stress response genes in transgenic Arabidopsis. As key components of the E3 ubiquitin ligase in the Skp1/Cullin or CDC53/F-box (SCF) complex, F-box proteins are involved in plant abiotic stress responses. However, the functions of F-box proteins in soybean in response to abiotic stress remain unclear. In this study, the soybean F-box protein-encoding gene GmFBX176 was cloned and functionally analyzed. GmFBX176 localized to the nucleus, was widely expressed in tissues (with the highest level in the roots), and responded to polyethylene glycol (PEG) treatment, abscisic acid (ABA) treatment, and salt stress at the transcriptional level. GmFBX176 -overexpressing Arabidopsis had lower survival rates; faster water loss rates; lower proline, sucrose and chlorophyll contents; greater malondialdehyde (MDA) contents; greater relative electrical conductivity (REC); and greater drought stress sensitivity than did wild-type (WT) Arabidopsis. Moreover, GmFBX176 -overexpressing Arabidopsis had lower survival rates, lower chlorophyll content, lower superoxide dismutase (SOD) activity, greater sensitivity to salt stress, longer roots, greater stomatal opening rates, and lower sensitivity to ABA than did WT Arabidopsis. Transcriptome sequencing and quantitative real-time PCR (qPCR) analyses revealed that GmFBX176 affects the transcript levels of stress response genes. These results indicate that GmFBX176 regulates ABA-mediated responses to drought and salt stress. [ABSTRACT FROM AUTHOR]