Glyoxalase pathway is a reactive carbonyl species (RCS) scavenging mechanism involved in the detoxification of methylglyoxal (MG), which is a reactive α-ketoaldehyde. In plants under abiotic stress, the cellular toxicity is reduced through glyoxalase pathway genes, i.e. Glyoxalase I (Gly I), Glyoxalase II (Gly II) and Glyoxalase III (Gly III). Salinity and water deficit stresses produce higher amounts of endogenous MG resulting in severe tissue damage. Thus, characterizing glyoxalase pathway genes that govern the MG metabolism should provide new insights on abiotic stress tolerance in Erianthus arundinaceus, a wild relative of sugarcane and commercial sugarcane hybrid (Co 86032). In this study, three glyoxalase genes (Glyoxalase I, II and III) from E. arundinaceus (a wild relative of sugarcane) and commercial sugarcane hybrid (Co 86032) were characterized. Comparative gene expression profiles (qRT-PCR) of Glyoxalase I, II and III under salinity and water deficit stress conditions revealed differential transcript expression with higher levels of Glyoxalase III in both the stress conditions. Significantly, E. arundinaceus had a higher expression level of glyoxalase genes compared to commercial sugarcane hybrid. On the other hand, gas exchange parameters like stomatal conductance and transpiration rate were declined to very low levels under both salt and drought induced stresses in commercial sugarcane hybrid when compared to E. arundinaceus. E. arundinaceus maintained better net photosynthetic rate compared to commercial sugarcane hybrid. The phylogenetic analysis of glyoxalase proteins showed its close evolutionary relationship with Sorghum bicolor and Zea mays. Glyoxalase I and II were predicted to possess 9 and 7 isoforms respectively whereas, Glyoxalase III couldn’t be identified as it comes under uncharacterized protein identified in recent past. Chromosomal mapping is also carried out for glyoxalase pathway genes and its isoforms. Docking studies revealed the binding affinities of glyoxalase proteins in both E. arundinaceus and commercial sugarcane hybrid with their substrate molecules. This study emphasizes the role of Glyoxalase pathway genes in stress defensive mechanism which route to benefit in progressive plant adaptations and serves as potential candidates for development of salt and drought tolerant crops.

This investigation aimed to optimize the time, pH, pressure, and temperature of sugarcane juice pasteurization and to develop a “ready to serve” bottled sugarcane juice with a high preservation efficiency. Fresh sugarcane juice was extracted from sugarcane genotype Co 89003, and beverage samples were collected using three different treatments: sulphitation of juice with the addition of potassium metabisulphite (KMS-25, 50, 100, and 150 ppm), acidification of juice (addition of citric acid, to reduce the pH of the juice to 4.8, 4.5, and 4.25), and steam treatment of the canes (5 min, 10, and 15 min at 7 psi). In all treatments, the juice was pasteurized in glass bottles @ 65 °C for 25 min and stored at low temperature (5 °C) in pre-sterilized glass bottles. Juice properties such as the ˚Brix, total sugar, pH, and total phenolic content decreased with storage, whereas the microbial count, titrable acidity, and reducing sugar content significantly increased during storage. The addition of KMS, citric acid, and the steam treatment reduced the browning of juice and maintained the color of juice during storage, by inhibiting the polyphenol oxidase enzyme activity, from 0.571 unit/mL to 0.1 unit/mL. Among the selected treatments, sugarcane juice with KMS (100 and 150 ppm) and steam treatment of the canes for 5 and 10 min at 7 psi showed the minimum changes in physico-chemical properties, sensory qualities, and restricted microbial growth. Thesulphitation treatment with pasteurization proved best for increasing the shelf life of sugarcane juice upto 90 days with refrigeration. Similarly, the steam-subjected cane juice (10 and 15 min at 7 psi) could be effectively preserved for upto 30 days with refrigeration, without any preservative.

The low temperature (LT) conditions that prevail during winter in subtropical regions of India drastically affect the growth and yield of sugarcane. To identify low-temperature-tolerant agronomical acceptable genotypes for immediate deployment as donor parents in the subtropical sugarcane breeding program, 34 sugarcane clones belonging to 7 genetically diverse groups were evaluated under three crop environments, viz., spring planting, winter ratoon and spring ratoon, during 2015–2016 and 2016–2017. In the winter ratoon crop, commercial cane sugar and cane yield were reduced, whereas sucrose % was increased over the spring planted crop and the spring ratoon crop. The wild species and introgressed hybrid groups showed improvement for yield and quality traits in the winter ratoon crop, whereas commercial and near commercial groups showed reduction for these traits over the plant and spring ratoon crops. The tropical cultivars group was the poorest performer irrespective of the traits and crops. Yield per se under a stress environment was adjudged as the best selection criteria. For classification of sugarcane clones according to their low temperature tolerance, an index named winter tolerance index (WTI) is proposed which takes into account the winter sprouting index (WSI), winter growth and yield per se of the winter ratoon crop. The WTI had significant positive association with WSI, cane yield, millable cane population and cane length. As per the WTI ratings, the wild species of Saccharum complex and introgressed hybrid groups were rated as excellent WT clones. Subtropical commercial or advanced generation groups were poor WT clones, and tropical commercial cultivars group were winter sensitive clones. Clones such as AS04-635, AS04-1687, IK76-48, GU07-2276, IND00-1040, IND00-1038 and IND00-1039 had excellent tolerance, and GU07-3849, AS04-245, Co 0238, AS04-2097 and GU07-3774 had good WTI scores. The variety, Co 0238, may be continued for cultivation under LT regions with prophylactic measurers for red rot, while other clones listed above may be utilized in subtropical breeding programs.