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Key message: Differentially expressed antioxidant enzymes, amino acids and proteins in contrasting rice genotypes, and co-location of their genes in the QTLs mapped using bi-parental population, indicated their role in salt tolerance. Abstract: Soil salinity is a major environmental constraint limiting rice productivity. Salt-tolerant 'CSR27', salt-sensitive 'MI48'and their extreme tolerant and sensitive recombinant inbred line (RIL) progenies were used for the elucidation of salt stress tolerance metabolic pathways. Salt stress-mediated biochemical and molecular changes were analyzed in the two parents along with bulked-tolerant (BT) and bulked-sensitive (BS) extreme RILs. The tolerant parent and BT RILs suffered much lower reduction in the chlorophyll as compared to their sensitive counterparts. Activities of antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) and non-enzymatic antioxidant ascorbic acid were much higher in salt-stressed CSR27 and BT RILs than MI48 and BS RILs. Further, the tolerant lines showed significant enhancement in the levels of amino acids methionine and proline in response to salt stress in comparison to the sensitive lines. Similarly, the tolerant genotypes showed minimal reduction in cysteine content whereas sensitive genotypes showed a sharp reduction. Real time PCR analysis confirmed the induction of methionine biosynthetic pathway (MBP) enzymes cystathionine-β synthase (CbS), S-adenosyl methionine synthase (SAMS), S-adenosyl methionine decarboxylase (SAMDC) and serine hydroxymethyl transferase (SHMT) genes in tolerant lines, suggesting potential role of the MBP in conferring salt tolerance in rice variety CSR27. Proteome profiling also confirmed higher expression of SOD, POD and plastidic CbS and other proteins in the tolerant lines, whose genes were co-located in the QTL intervals for salt tolerance mapped in the RIL population. The study signifies integrated biochemical-molecular approach for identifying salt tolerance genes for genetic improvement for stress tolerant rice varieties. [ABSTRACT FROM AUTHOR]

Cajanus cajan (L) Millsp. (Sanskrit: Adhaki, Hindi: Arhar, English: Pigeon pea, Bengali: Tur) (family: Fabaceae) is the most important grain legume crop of rain-fed agriculture in semi-arid tropics. It is both a food crop and a cover/forage crop with high levels of proteins and important amino acids like methionine, lysine and tryptophan. During the last few decades extensive studies have been carried out regarding the chemistry of C. cajan and considerable progress has been achieved regarding its biological activities and medicinal applications. This review article gives an overview on the biological activities of the compounds isolated, pharmacological actions and clinical studies of C. cajan extracts apart from its general details. [ABSTRACT FROM AUTHOR]