Simultaneous Expression of PDH45 with EPSPS Gene Improves Salinity and Herbicide Tolerance in Transgenic Tobacco Plants

Abstract

To cope with the problem of salinity- and weed-induced crop losses, a multi-stress tolerant trait is need of the hour but a combinatorial view of such traits is not yet explored. The overexpression of PDH45 (pea DNA helicase 45) and EPSPS (5-enoylpruvyl shikimate-3-phosphate synthase) genes have been reported to impart salinity and herbicide tolerance. Further, the understanding of mechanism and pathways utilized by PDH45 and EPSPS for salinity and herbicide tolerance will help to improve the crops of economical importance. In the present study, we have performed a comparative analysis of salinity and herbicide tolerance to check the biochemical parameters and antioxidant status of tobacco transgenic plants. Collectively, the results showed that PDH45 overexpressing transgenic lines display efficient tolerance to salinity stress, while PDH45+EPSPS transgenics showed tolerance to both the salinity and herbicide as compared to the control [wild type (WT) and vector control (VC)] plants. The activities of the components of enzymatic antioxidant machinery were observed to be higher in the transgenic plants indicating the presence of an efficient antioxidant defense system which helps to cope with the stress-induced oxidative-damages. Photosynthetic parameters also showed significant increase in PDH45 and PDH45+EPSPS overexpressing transgenic plants in comparison to WT, VC and EPSPS transgenic plants under salinity stress. Furthermore, PDH45 and PDH45+EPSPS synergistically modulate the jasmonic acid and salicylic acid mediated signaling pathways for combating salinity stress. The findings of our study suggest that pyramiding of the PDH45 gene with EPSPS gene renders host plants tolerant to salinity and herbicide by enhancing the antioxidant machinery thus photosynthesis.

Pyramiding of γ‐TMT and gly I transgenes in Brassica juncea enhances salinity and drought stress tolerance

“…Accumulation of ROS during abiotic stress leads to the accumulation of MDA and damages to cellular membranes, making them leaky, which ultimately results in the outflow of ions that are vital for proper cell functioning (Garg et al, 2017; Raina et al, 2021). We observed lower amounts of MDA and ion leakage in the CB lines than in γ‐TMT , gly I , and WT lines under stress conditions.…”

“…The relative tolerance of WT, γ‐TMT , gly I, and CB lines was also assessed by examining stress markers like RWC, proline content, electrolyte leakage, and MDA content under salt and mannitol stress. Plants with higher photosynthetic capacity and lower rates of water loss often have enhanced tolerance or resistance to environmental stresses (Garg et al, 2017; Negi et al, 2016; Singh et al, 2016). The RWC is a parameter often used to assess the water retention capacity of plants (Kumar et al, 2013a).…”

“…Plants with higher photosynthetic capacity and lower rates of water loss often have enhanced tolerance or resistance to environmental stresses (Garg et al, 2017;Negi et al, 2016;Singh et al, 2016). The RWC is a parameter often used to assess the water retention capacity of plants (Kumar et al, 2013a).…”

Marker-Free Rice (Oryza sativa L. cv. IR 64) Overexpressing PDH45 Gene Confers Salinity Tolerance by Maintaining Photosynthesis and Antioxidant Machinery

“…We developed the method to select marker and reporter free transgenic lines using the previously published reports [46,47]. In this research, marker-free PDH45 transgenic rice plants were raised using Agrobacterium-mediated transformation followed by screening with 200 mM NaCl in selection, shoot, and root regeneration media to select only the transformed calli for plant regeneration because PDH45 is responsible for salinity tolerance [31][32][33]45]. The elevated stress tolerance in PDH45-expressing plants correlated with MH1 (M. sativa helicase 1) transgenic plants, showing that MH1 functions in abiotic stress tolerance by elevating reactive oxygen species (ROS) burden and through osmotic adjustment [48].…”

“…We modified the media described by Sahoo and Tuteja [28]. Here, we used 200 mM NaCl in place of hygromycin as the gene PDH45 has already been reported as being responsible for salinity tolerance in different plants [29][30][31][32][33][34]. The other compositions of media were the same as described earlier [28].…”