Physiological and molecular mechanism of tolerance of two maize genotypes under multiple abiotic stresses.

Abiotic stresses are the major threat to crops regardless of their nature, duration, and frequency, their occurrence either singly, and or combination is deleterious for the plant growth and development. Maize is the most important crop largely grown in the tropical regions in the summer rainy season, often facing a stress combination of drought and waterlogging. We previously showed under multiple stresses up-regulated leaf proteins of maize plants were involved to enhance the tolerance mechanism of tolerant genotype. Whereas, in susceptible genotypes up-regulated proteins ameliorate to survive the stressful condition. Further to understand the response of roots proteome under multiple stresses was determined using the 2DE technique. The results of the root proteome show the up-regulated proteins of CML49 genotype (tolerant) are involved in enhancing the N content, cell wall remodeling, and acclimatization during the stresses. Up-regulated proteins of CML100 genotype (sensitive) are stressed markers of roots' primary and secondary metabolism. However, the root proteome of both genotypes correlates with the leaf proteome (previous). Therefore, the present study and our previous results provide comprehensive insight into the molecular mechanisms of tolerance in multiple abiotic stresses of maize plants.

Root proteome alterations in sugarcane promoted by the regrowth cycle in commercial production

The decrease in agricultural productivity in successive cutting of sugarcane plants is associated with several extrinsic and intrinsic factors. However, no studies have focused on the physiological potential of sett roots in successive cuts in sugarcane culture. There have been no proteomic studies on sugarcane sett roots at different stages of cutting. In this study, the UPLC-ESI-TOF-MS system and bioinformatics tools were used to identify proteins of sett roots in the first and fifth cuts of sugarcane cultivar RB966928 in the sprouting stage. Differences in the proteome of sett roots of RB966928 in the first and fifth cuts detected in this study supports the hypothesis that the proteome of sett roots may change after successive cuts in sugarcane culture. A reduction in the number of proteins was observed in the roots of the fifth cut, whereas 34% of proteins, identified exclusively in the first cut, were absent in the fifth cut. Proteome analysis of sett roots in the first and fifth cuts showed that the changes after successive cuts were quantitative (number of proteins) and mainly qualitative. In this study, the detailed list of proteins identified in the first cut but absent in the fifth cut is relevant. The findings of this study may aid further research that employ biotic or abiotic elicitors to induce gene expression of essential proteins absent in sett roots of the fifth cut, and thus increasing the agricultural productivity and longevity of cane fields