Abstract:
Water deficit is escalating day by day due to global warming, with more abrupt changes in evapotranspiration of crops leading to physiochemical and molecular changes in adaptability and tolerance of plants. Although, important sources of variation for drought tolerance exist in wild relatives, the mechanisms and the key genes controlling tolerance in tomato are little known. Manipulation of the key genes and proteins and convergence of gene regulatory pathways may aid in the process of counteracting multiple stresses. This study investigates the physiological and molecular responses in leaves of cv. Riogrande plants transformed with Lotus japonicas (LjCCD7) a biosynthetic precursor gene in strigolactones synthetic pathway. Transgenic plants without stress and moderate and/or severe drought stress displayed significant physiological differences as compared to wild type plants. The leaves of T1 plants showed greater ability to avoid water loss and oxidative damage. Under drought stress, the ABA content significantly increased in the LjCCD7overexpressing plants, inducing stomatal closure and reducing water loss, which underlay the plants' enhanced stress tolerance. Furthermore, scavenging reactive oxygen species (ROS), higher total chlorophyll content, lower lipid peroxidation levels, increased peroxidase activities (including APX, CAT, POD and SOD) and higher levels of proline were observed in LjCCD7-overexpressing plants. Significant increase in polyphenols, flavonoids and antioxidant compounds were observed in methanolic extractsof transgenic fruits and leaves as compared to control tissue suggesting a positive role of CCD7 gene in improvement of antioxidant defence system. These results indicate that overexpression of LjCCD7in transgenic tomato improves drought tolerance through ABA synthesis and the elimination of ROS which is due to organ level dynamics of SL in ABA dependent manner. The natural and synthetic SLs are stereo specifically required by land plants to orchestrate hormonal cross talk and stress resilience. LjCCD7gene, when upregulated in tomato not only altered the architecture of transgenic plants, but also enhanced their adaptability to drought stress by increasing water use efficiency (WUE). The Transgenic root stocks may be further utilized to create SL+/WT heterograft for improved WUE and improved nutrient utilization.
Page(s):
392-392
DOI:
DOI not available
Published:
Journal: Abstract Book on International Conference on Food and Applied Sciences (ICFAS-23) 3-5 August 23, Volume: 0, Issue: 0, Year: 2023
Keywords:
water use efficiency
,
Reactive oxygen species
,
abiotic stress
,
carotenoid
,
Strigolactones
,
cleavage CCD7