Overexpression of AtNCED3 gene improved drought tolerance in soybean in greenhouse and field conditions

Abstract

Water deficit is an important climatic problem that can impair agriculture yield and economy. Genetically modified soybean plants containing the AtNCED3 gene were obtained aiming drought-tolerance improvement. The NCED3 gene encodes a 9-cis-epoxycarotenoid dioxygenase (NCED, EC 1.13.11.51), an important enzyme in abscisic acid biosynthesis. ABA activates the expression of drought-responsive genes, in water-deficit conditions, targeting defense mechanisms and enabling plants to survive under low water availability. Results from greenhouse experiments showed that the transgene AtNCED3 and the endogenous genes GmAREB1, GmPP2C, GmSnRK2 and GmAAO3 presented higher expression under water deficit (WD) in the event 2Ha11 than in WT-plants. No significant correlation was observed between the plant materials and WD conditions for growth parameters; however, gas exchange measurements decreased in the GM event, which also showed 80% higher intrinsic water use when compared to WT plants. In crop season 2015/16, event 2Ha11 showed higher total number of pods, higher number of pods with seeds and yield than WT plants. ABA concentration was also higher in GM plants under WD. These results obtained in field screenings suggest that AtNCED3 soybean plants might outperform under drought, reducing economic and yield losses, thus being a good candidate line to be incorporated in the soybean-breeding program to develop droughttolerant cultivars.

Overexpression of full-length and partial DREB2A enhances soybean drought tolerance

“…Previous studies evaluated the expression level of dehydrin in response to abiotic stresses and showed increased levels in response to osmotic stress (Chiappetta et al, 2015), ABA, salicylic acid, and methyl jasmonate application, and drought, cold and, heat stresses in grapevine (Yang et al 2012). Specifically, in soybean GM with different transcriptional factors, higher expression levels of LEA2 and LEA6 genes under WD were identified (Honna et al, 2016;Fuganti-Pagliarini et al, 2017;Molinari et al, 2020), corroborating the results obtained in the current study.…”

“…The mean length of internodes corresponded to the ratio between H1 and H2 and the number of nodes. The relative growth rate in height (RGRH) was calculated according to Molinari et al (2020). Total leaf area was measured using a leaf area meter (LI 3100C).…”

Endogenous indole-3-acetamide levels contribute to the crosstalk between auxin and abscisic acid, and trigger plant stress responses in Arabidopsis

“…RD26A , COR47 , ERD4 , ERD9 , and ERD10 , the gene for a key-enzyme of ABA synthesis, NCED3 , appeared strongly induced in ami1-2 . The overexpression of NCED3 has recently been associated with an improvement of drought tolerance in soybean ( Molinari et al , 2020 ). Both the induction of NCED3 through IAM application and the accumulation of ABA in the ami1 alleles could be confirmed ( Fig.…”

Physiological and Molecular Responses of ‘Dusa’ Avocado Rootstock to Water Stress: Insights for Drought Adaptation

“…In particular, serine protease inhibitors play an important role in cell survival, development, and host defense, i.e., transgenic Arabidopsis thaliana plants overexpressing serine protease inhibitors showed higher RWC, reduced lipid peroxidation, and enhanced activity of antioxidant glutathione-S-transferase [61]. This cluster also grouped four genes encoding the 9-cis-epoxycarotenoid dioxygenase (NCED), involved in ABA biosynthesis and related to dehydration stress tolerance in Arabidopsis [43,[62][63][64]. Interestingly, NCED genes showed higher FC values under mild-WS than in severe-WS, indicating that they are involved in the early response to water deficit.…”