Salinity and drought-induced methylglyoxal detoxification in Brassica spp. and purification of a high active glyoxalase I from tolerant genotype

Abstract

This experiment was conducted to study the role of glyoxalase system in conferring salinity and drought stress in Brassica spp. Two Brassica genotypes viz. BARI Sharisha16 (tolerant) and Tori7 (susceptible) were exposed to salt (16 dS m -1 ) and drought for 2, 4 and 6 days. The comparative study of two Brassica genotypes under salinity and drought stresses revealed that BARI Sharisha16 is more tolerant than Tori7 in both stresses. Under drought stress and salinity stress, Gly I activity increased significantly in both genotypes. Notably, concomitant increased activities of Gly I and Gly II with increased methylglyoxal (MG) suggested their role in MG detoxification in Brassica Spp. At six-day of salt stress, it was remarkable that Gly I and Gly II activities were 49 and 36 % higher in BARI Sharisha16 than Tori7. In addition, Gly I and Gly II activities were 24 and 21 % higher in BARI Sharisha16 than Tori7 after sixth day of drought, and hence, using different column chromatography Gly I was purified from BARI Sharisha16 seedlings. In purification, the fraction eluted from affinity chromatography showed specific activity of 173.51 µM min -1 mg -1 protein. In SDS-PAGE, the purified Gly I protein migrated as a single band on with an apparent molecular mass of 27 kDa. In final purification, the recovery of Gly I activity was 0.38% along with purification fold 112.7. In this study, role of glyoxalase system in detoxification of MG was observed and subsequently, Gly I was purified from tolerant genotypes.

Involvement of l-Cysteine Desulfhydrase and Hydrogen Sulfide in Glutathione-Induced Tolerance to Salinity by Accelerating Ascorbate-Glutathione Cycle and Glyoxalase System in Capsicum

“…The plants subjected to SS showed high MG accumulation, as was observed in mung bean [ 30 ], Brassica spp. [ 122 ], and tomato [ 10 ] under SS. The glyoxalase system consists of two enzymes (Gly I and Gly II) to detoxify the overgeneration of methylglyoxal (MG) by consuming GSH as a substrate and thereby causes enhanced stress tolerance [ 123 , 124 ].…”

“…In this study, increased GSH content under SS due to GSH treatment reduced the MG accumulation, thereby reducing oxidative stress in the pepper plants. Another strategy to reduce the MG accumulation is to upregulate the glyoxalase-system-related enzymes, Gly I and Gly II, in many plant species under stress conditions [ 122 ]. In the present study, SS increased the activity of Gly I, but decreased that of Gly II in the pepper plants, similar to what was observed in Brassica napus [ 20 ], tomato [ 125 ], and soybean [ 21 ].…”

Glyoxalase I activity affects Arabidopsis sensitivity to ammonium nutrition

“…The differences of crop cultivars in their resistance to stress were also indicated to be correlated with accession-dependent efficiency of the glyoxalase systems and thus with tissue levels of MG (Hossain et al 2016 ). It has also been shown that genetically forced increases in expression of GLXI and/or GLXII (Singla-Pareek et al 2003 , 2006 ; Saxena et al 2011 ; Devanathan et al 2014 ; Zeng et al 2016 ; Batth et al 2020 ) may significantly improve plant stress resistance and could help in the development of crop varieties resistant to environmental stresses (Gupta et al 2018 ).…”