A New Comprehensive Evaluation System for Thermo-Tolerance in Tomato at Different Growth Stage

With global warming, heat stress is becoming a more frequent event and a major limiting factor for crop production. The evaluation of thermo-tolerance is essential for the cultivators to obtain the heat resistant genotypes and breeders to improve the thermo-tolerance of plants. Therefore, it is very important to perfect the existing evaluation system for thermo-tolerance. In this study, 30 tomato genotypes were treated with heat stress at germination, seedling and flowering stages. Each index was different and diverse in different tomato genotypes by doing variability analysis, difference analysis and Student＇s t test. Before principal component analysis （PCA）, a positive treatment for the negative and moderation indexes was performed. After correlation analysis, the authors performed PCA （including dimensionality reduction （DR）, no dimensionality reduction （NDR） and optimal index （OI））, combining with subordinate function （SF）, weight and cluster analysis. No matter at germination or seedling stage, the members of the groups were basically identical for DR, NDR and OI. Then 10 tomato genotypes were chosen from 30 randomly for verification. Compared all the evaluation systems, OI was the simplest and also could get as credible results as other methods. Therefore, in this study, OI could be adopted and improve the efficiency during the evaluation. At germination stage, germination power （GP） can accurately evaluate the thermo-tolerance, and at seedling stage, it was fresh weight （FW）, internode length （IL） and dry matter percentage of seedling （DMP）. Finally, all the indexes in the three stages were applied correlation analysis. Seedling stage showed significant positive correlation with flowering stage. In conclusion, this work improves the current system and set up a new comprehensive evaluation method named OI, which also improves the efficiency, guarantees reliability in screening thermo-tolerance of tomato for cultivators and expedites the process of breeding for resistance.

Prospects of HSP70 as a genetic marker for thermo-tolerance and immuno-modulation in animals under climate change scenario

Heat stress induced by long periods of high ambient temperature decreases animal productivity,leading to heavy economic losses.This devastating situation for livestock production is even becoming worse under the present climate change scenario.Strategies focused to breed animals with better thermotolerance and climatic resilience are keenly sought these days to mitigate impacts of heat stress especially in high input livestock production systems.The 70-kDa heat shock proteins(HSP70) are a protein family known for its potential role in thermo-tolerance and widely considered as cellular thermometers.HSP70 function as molecular chaperons and have major roles in cellular thermotolerance,apoptosis,immune-modulation and heat stress.Expression of HSP70 is controlled by various factors such as,intracellular pH,cyclic adenosine monophosphate(cyclic AMP),protein kinase C and intracellular free calcium,etc.Over expression of HSP70 has been observed under oxidative stress leading to scavenging of mitochondrial reactive oxygen species and protection of pulmonary endothelial barrier against bacterial toxins.Polymorphisms in flanking and promoter regions in HSP70 gene have shown association with heat tolerance,weaning weight,milk production,fertility and disease susceptibility in livestock.This review provides insight into pivotal roles of HSP70 which make it an ideal candidate genetic marker for selection of animals with better climate resilience,immune response and superior performance.

Application of Potent Actinomycete Strains for Bio-Degradation of Domestic Agro-Waste by Composting and Treatment of Pulp-Paper Mill Effluent

Actinomycetes are known to produce an extensive range of bioactive compounds as well as variety of enzymes having multiple biotechnological applications. They are an important source of lignocellulose hydrolyzing enzymes and constitute considerable proportion of the soil or aquatic micro-flora responsible for degradation of biomass in natural environment. Presently, most of the commercially exploited lignocellulases and commercial biodegradation processes rely mostly on fungal or bacterial micro-organisms. Actinomycetes are relatively less explored for biodegradation processes that utilize lignocellulases for solid agro-waste management and waste water treatment. There is also a need to search and explore novel actinomycete strains for various biodegradation applications. This study involved examining the possibility of using only potent actinomycetes strains for the composting process by creating the consortium of such strains that could produce thermo-tolerant and alkali-tolerant key enzymes necessary for the degradation of cellulose, hemi-cellulose and lignin. The newly developed actinomycete consortium was tested for the composting activity and the composting process was optimized. The analysis of the composted material generated under ideal condition, demonstrated desirable physical and chemical characteristics. Paper pulp effluent poses a hazard to waterways due to toxicity. The toxicity of this mill effluent can be attributed to a compound called lignin and its chlorinated derivatives that are let out during the treatment of lignocellulosic constituents. Current study also involves the use of a strain of actinomycete having ability to produce enzyme laccase, which is active under alkaline condition for the treatment of paper pulp effluent. Enzyme laccase is known for its ability to attack phenolic components of lignin and common hazardous component of effluent, polycyclic aromatic hydrocarbons (PAH). Aerobic treatment of effluent by actinomycete strain indicated 21% reduction in COD at pH 7.5 after 14 days under optimum condition. This strain was identified as Streptomyces rochei based on molecular fingerprinting and was reported to be the producer of laccase probably for the first time. LCMS analysis of the treated effluent sample showed the presence of degradation compounds forming after 7 and 14 days of treatment. These compounds showed the degradation of lignin components and other phenolic, non-phenolic components of the effluent by intra molecular re-arrangement, oxidation and ring opening reactions. Overall, potent thermo-tolerant and alkali-tolerant actinomycete strains were successfully isolated and applied for bio-degradation of domestic agro-waste by composting and treatment of pulp-paper mill effluent. The consortium of these strains may be further utilized for scale-up studies in order to assess its commercial feasibility for biodegradation processes.