Search

Drought stress is considered a severe threat to crop production. It adversely affects the morpho-physiological, biochemical and molecular functions of the plants, especially in short duration crops like mungbean. In the past few decades, significant progress has been made towards enhancing climate resilience in legumes through classical and next-generation breeding coupled with omics approaches. Various defence mechanisms have been reported as key players in crop adaptation to drought stress. Many researchers have identified potential donors, QTLs/genes and candidate genes associated to drought tolerance-related traits. However, cloning and exploitation of these loci/gene(s) in breeding programmes are still limited. To bridge the gap between theoretical research and practical breeding, we need to reveal the omics-assisted genetic variations associated with drought tolerance in mungbean to tackle this stress. Furthermore, the use of wild relatives in breeding programmes for drought tolerance is also limited and needs to be focused. Even after six years of decoding the whole genome sequence of mungbean, the genome-wide characterization and expression of various gene families and transcriptional factors are still lacking. Due to the complex nature of drought tolerance, it also requires integrating high throughput multi-omics approaches to increase breeding efficiency and genomic selection for rapid genetic gains to develop drought-tolerant mungbean cultivars. This review highlights the impact of drought stress on mungbean and mitigation strategies for breeding high-yielding drought-tolerant mungbean varieties through classical and modern omics technologies.

To transfer the 2S chromosomal fragment(s) of Aegilops kotschyi (2S(k)) into the bread wheat genome which could lead to the biofortification of wheat with high grain iron and zinc content.Wheat-Ae. kotschyi 2A/2S(k) substitution lines with high grain iron and zinc content were used to transfer the gene/loci for high grain Fe and Zn content into wheat using seed irradiation approach.Bread wheat plants derived from 40 krad-irradiated seeds showed the presence of univalents and multivalents during meiotic metaphase-I. Genomic in situ hybridization analysis of seed irradiation hybrid F2 seedlings showed several terminal and interstitial signals indicated the introgression of Ae. kotschyi chromosome segments. This proves the efficacy of seed radiation hybrid approach in gene transfer experiments. All the radiation-treated hybrid plants with high grain Fe and Zn content were analyzed with wheat group 2 chromosome-specific polymorphic simple sequence repeat markers to identify the introgression of small alien chromosome fragment(s).Radiation-induced hybrids showed more than 65% increase in grain iron and 54% increase in Zn contents with better harvest index than the elite wheat cultivar WL711 indicating effective and compensating translocations of 2S(k) fragments into wheat genome.

In the present study we aimed to characterize the interspecific hybrids made between Triticum aestivum cv. Pavon monosomic for chromosome 5B with different accessions of Aegilops kotschyi (UUSS) and Aegilops peregrina (UUSS) at cytological, molecular and morphological basis. Molecular analysis using Ph1 locus specific dominant marker and cytological analysis clearly differentiated between F1 hybrids (ABDUS) with and without 5B chromosome. Plants without chromosome 5B showed stunted and bushy growth habit with reduced height and more number of tillers per plant while those with 5B plants showed normal growth. Agreement of morphological observations with the cytological and molecular results indicates that the morphological characteristics could also be used to screen plants without 5B chromosome. The results clearly demonstrated that the absence of chromosome 5B through the use of Pavon monosomic for chromosome 5B can be an efficient way to induce homoeologous pairing between chromosomes of wheat and Aegilops species for precise introgression of useful variability.

Iron (Fe) and zinc (Zn) contents in hexaploid wheat are very low and are further reduced because of the removal of micronutrient-rich bran of wheat grains during milling and processing. Therefore, hexaploid wheat, its wild species and wheat–Aegilops kotschyi substitution lines were evaluated to identify the genome(s) carrying gene(s) for high Fe and Zn concentrations in bran and endosperm fractions of grains. It is reflected from the results that Triticum monococcum (acc. W463) may serve as a promising donor for biofortification of Fe, and Aegilops speltoides (acc. 3804) may serve as a promising donor for biofortification of Zn in the endosperm of cultivated wheat. Further, among the three wheat–Ae. kotschyi substitution lines, the higher concentration of Fe and Zn in endosperm fraction was observed in BC2F4 63-2-13-1. The work on precise transfer of useful gene(s) from 7Uk chromosome of this line is in progress to reduce linkage drag.

Thirty different wheat genotypes, including landraces, cultivars, and related wild species, were analyzed for puroindoline genes and proteins. Full-length Pina and Pinb genes were amplified using gene-specific markers where 13 genotypes amplified both genes, while 17 genotypes had either one or none of the puroindoline genes. None of the puroindoline genes were detected in any of the Triticum durum cultivars. Genotypes with both puroindoline genes had a soft grain texture, while other genotypes had hard grains. Related nonprogenitor species with A, C, M, U, and S genomes also showed the presence of either one or both the puroindoline genes, indicating that these species can also be utilized for development of extra-soft wheat. SDS-PAGE analysis of selected wheat genotypes revealed that puroindoline proteins are approximately 13-14 kDa and the protein results were in agreement with the PCR results. Puroindoline proteins of selected 3 soft wheat genotypes HPW 89, Naphal, and IITR-9 also exhibited antimicrobial activity against gram-positive and gram-negative bacteria. Both genes of a soft wheat cultivar, HPW 89, were successfully cloned in the Escherichia coli DH-5 $\alpha$ strain. Introgression and molecular characterization of diverse Pina and Pinb genes to develop extra-soft wheat is in progress.

Half of the world population suffers from deficiencies in micronutrients—iron, zinc, vitamin A—largely among the people of developing countries depending on staple cereals, and these deficiencies may lead to health risks and even death in acute cases. The staple food crops are inherently low in micronutrients, and these are further reduced during grain and food processing. Among the various strategies to combat micronutrient malnutrition, biofortification may prove to be the most economical, feasible, and sustainable approach to increase the mineral content of staple food crops. Biofortified crops also bear the potential to enhance the agronomic efficiency of plants on mineral-poor soils. Biofortification involving enhanced uptake of minerals from soil, their transport to the leaves, and improved sequestration in the edible tissues of grains, is being done through combination of conventional and molecular breeding and genetic engineering. Bioavailability of micronutrients from cereal-based diets is also crucial and can be enhanced by lowering the anti-nutritional compounds like phytic acid and simultaneously increasing promoters of mineral absorption, such as ascorbic acid, inulin, and β-carotene. Thorough understanding of the molecular basis of micronutrient uptake, transport, and deposition in various grain tissues will further strengthen the biofortification program to enhance the micronutrients and minimize their losses during processing.

During the recent decades, awareness towards the role of essential fatty acids in human health and disease prevention has been unremittingly increasing among people. Fish, fish oils and some vegetable oils are rich sources of essential fatty acids. Many studies have positively correlated essential fatty acids with reduction of cardiovascular morbidity and mortality, infant development, cancer prevention, optimal brain and vision functioning, arthritis, hypertension, diabetes mellitus and neurological/neuropsychiatric disorders. Beneficial effects may be mediated through several different mechanisms, including alteration in cell membrane composition, gene expression or eicosanoid production. However, the mechanisms whereby essential fatty acids affect gene expression are complex and involve multiple processes. Further understanding of the molecular aspects of essential fatty acids will be the key to devising novel approaches to the treatment and prevention of many diseases.

The antioxidant activity of extracts of different polarity from seeds of Local variety of Coriandrum sativum was assessed via both in vitro and ex vivo models. Results indicate that hexane extract of coriander exhibited no appreciable affects at either of the concentrations in all the three in vitro free radical scavenging models i.e. hydroxyl radical, super oxide radical and nitric oxide radical. Instead, it showed prooxidant activity at higher concentrations. Whereas methanol: hexane extracts of coriander were found to be ineffective in quenching hydroxyl radical but revealed only moderate activity in quenching super oxide radical (EC50=711.81 μg/ml) and nitric oxide radical (EC50=569.02 μg/ml). Only methanolic extract of Local variety offered strong antioxidant activity in a concentration dependent manner for the same three free radicals with EC50 of 18.33 μg/ml, 553.50 μg/ml and 179.53 μg/ml respectively. Even in vitro linoleic acid peroxidation model proved methanolic extract of coriander (80% inhibition till 48 h) to be far better than standard antioxidant ascorbic acid (70% inhibition till 12 h). EC50 and SC50 for ex vivo linoleic acid peroxidation of rat liver homogenate and erythrocytes were recorded as 383.10 μg/ml and 166.78 μg/ml respectively. The methanolic extract of Local variety was further evaluated for its protective effect on osmotic fragility and antioxidant enzymes of erythrocytes at various time intervals (24–96 h). The decrease in% hemolysis and protection of activities of antioxidant enzymes even for 96 h of incubation in test groups supplemented with coriander proved indubitably, the effectiveness of methanolic coriander extract in alleviating protective mechanisms.

Micronutrient deficiency (Iron and Zinc) is the major problem worldwide mostly in the developing countries with high dependence on staple foods. Biofortification of staple cereal and tuber crops has been considered and taken up as the most effective, feasible and economic approach for alleviating micronutrient deficiency. The present study was the initiative towards biofortification of wheat where the previous work of wide hybridization between HD2687 and Aegilops longissima accession 3506 and subsequent backcrossing with Triticum aestivum cultivar WL711 has been continued. In this study the alien chromosome introgression, chromosomal stability of BC1F6 and BC2F4 wheat-Ae. longissima derivatives has been investigated for their potential as germplasm for future breeding and biofortification program through morphological, cytological and biochemical analysis. We found that the selected derivatives showed stable 42, 44 and 46 chromosomes for most of the plants where single plant reported for each 41, 43 and 45 chromosomes with 19–22 bivalents and few trivalent. The GISH analysis of derivative 79-1-4-8-1-2-2 revealed introgression of two univalent Sl chromosomes. Finally four derivatives were selected from BC1F6 (79-1-4-8-10-2-2, 79-1-4-8-10-2-5, 79-2-4-4-1-1-3 and 79-2-4-4-1-1-5) and three from BC2F4 (HD2687/L3506//WL711-3///WL711-1-2-7-1, HD2687/L3506//WL711-3///WL711-1-2-7-3, HD2687/L3506//WL711-3///WL711-1-2-7-5) as stable biofortified lines for future breeding to alleviate hidden hunger.