Overexpression of an Apocynum venetum DEAD-Box Helicase Gene (AvDH1) in Cotton Confers Salinity Tolerance and Increases Yield in a Saline Field

Abstract

Soil salinity is a major environmental stress limiting plant growth and productivity. We have reported previously the isolation of an Apocynum venetum DEAD-box helicase 1 (AvDH1) that is expressed in response to salt exposure. Here, we report that the overexpression of AvDH1 driven by a constitutive cauliflower mosaic virus-35S promoter in cotton plants confers salinity tolerance. Southern and Northern blotting analyses showed that the AvDH1 gene was integrated into the cotton genome and expressed. In this study, the growth of transgenic cotton expressing AvDH1 was evaluated under saline conditions in a growth chamber and in a saline field trial. Transgenic cotton overexpressing AvDH1 was much more resistant to salt than the wild-type plants when grown in a growth chamber. The lower membrane ion leakage, along with increased activity of superoxide dismutase, in AvDH1 transgenic lines suggested that these characteristics may prevent membrane damage, which increases plant survival rates. In a saline field, the transgenic cotton lines expressing AvDH1 showed increased boll numbers, boll weights and seed cotton yields compared with wild-type plants, especially at high soil salinity levels. This study indicates that transgenic cotton expressing AvDH1 is a promising option for increasing crop productivity in saline fields.

Genome-wide association reveals genetic variation of lint yield components under salty field conditions in cotton (Gossypium hirsutum L.)

“…GWAS analyses of BNPP are relatively rare, especially under salt stress. Our studies showed that salt stress can lead to a significant decrease in boll number per plant, which was consistent with previous reports [40,50], indicating that boll number is the first limiting factor for increasing cotton lint yield under stress environments. We also found that the number of repeated QTLs associated with BNPP was low under different salt conditions, implying a complex regulatory mechanism for BNPP.…”

“…Several reports have suggested that lint yield can be improved by altering the expression of salt-tolerance genes in cotton. For example, overexpressing AvDH1 in cotton can decrease membrane ion leakage, and increase the activity of superoxide dismutase, leading to salinity tolerance and increased yield [50]. Overexpression of SNAC1, which belongs to the stress-related NAC superfamily of transcription factors, could improve drought and salt tolerance by enhancing root development and reducing transpiration rate [57].…”

Genome-wide association study reveals genetic variation and candidate genes of lint yield components under salt field conditions in cotton (Gossypium hirsutum L.)

“…GWAS analysis on BNPP are relatively rare, especially under salt stress. Our studies showed that salt stress can lead to a significant decrease in boll number per plant which was consistent with previous reports [46,52], indicating that boll number is the first limiting factor for increasing cotton lint yield under stress environments. We also found the overlapped QTLs associated with BNPP was few under different salt conditions, implying a complex regulatory mechanism for BNPP production.…”

“…Several reports have suggested that the lint yield can be improved by altering the expression of salttolerant genes in cotton. For example, overexpressing AvDH1 can decrease membrane ion leakage, along with increased activity of superoxide dismutase and lead to salinity tolerance and increasing yield in cotton [52]. Overexpression SNAC1, which belongs to the stress-related NAC superfamily of transcription factors, could improve drought and salt tolerance by enhancing root development and reducing transpiration rate in transgenic cotton [56].…”

Genome-wide association reveals genetic variation of lint yield components under salty field conditions in cotton (Gossypium hirsutum L.)

“…Several reports have suggested that lint yield can be improved by altering the expression of salttolerance genes in cotton. For example, overexpressing AvDH1 in cotton can decrease membrane ion leakage, and increase the activity of superoxide dismutase, leading to salinity tolerance and increased yield [50]. Overexpression of SNAC1, which belongs to the stress-related NAC superfamily of transcription factors, could improve drought and salt tolerance by enhancing root development and reducing transpiration rate [57].…”