Publications

Breeding crop plants with increased yield potential and improved tolerance to stressful environments is critical for global food security. Drought stress (DS) adversely affects agricultural productivity worldwide and is expected to rise in the coming years. Therefore, it is vital to understand the physiological, biochemical, molecular, and ecological mechanisms associated with DS. This review examines recent advances in plant responses to DS to expand our understanding of DS-associated mechanisms. Suboptimal water sources adversely affect crop growth and yields through physical impairments, physiological disturbances, biochemical modifications, and molecular adjustments. To control the devastating effect of DS in crop plants, it is important to understand its consequences, mechanisms, and the agronomic and genetic basis of DS for sustainable production. In addition to plant responses, we highlight several mitigation options such as omics approaches, transgenics breeding, genome editing, and biochemical to mechanical methods (foliar treatments, seed priming, and conventional agronomic practices). Further, we have also presented the scope of conventional and speed breeding platforms in helping to develop the drought-smart future crops. In short, we recommend incorporating several approaches, such as multi-omics, genome editing, speed breeding, and traditional mechanical strategies, to develop drought-smart cultivars to achieve the 'zero hunger' goal.

Computer aided x-ray microtomography is an increasingly popular method to investigate the structure of materials. Continuing improvements in the technique are resulting in increasingly larger data sets. The analysis of these data sets generally involves executing a static workflow for multiple samples and is generally performed manually by researchers. Executing these processes requires a significant time investment. A workflow which is able to automate the activities of the user would be useful. In this work, we have developed an automated workflow for the analysis of microtomography scanned bread dough data sets averaging 5 GB in size. Comparing the automated workflow with the manual workflow indicates a significant amount of the time spent (33% in the case of bread dough) on user interactions in manual method. Both workflows return similar results for porosity and pore frequency distribution. Finally, by implementing an automated workflow, users save the time which would be required to manually execute the workflow. This time can be spent on more productive tasks.

Salinity is a major abiotic stress that is a global threat to crop production, including chickpea. This study focused on understanding the complex molecular mechanisms underlying salinity tolerance using comparative transcriptome analysis of tolerant (ICCV 10, JG 11) and sensitive (DCP 92-3, Pusa 256) chickpea genotypes in control and salt-stressed environments. A total of 530 million reads were generated from root samples of four genotypes using Illumina HiSeq-2500. A total of 21,698 differentially expressed genes (DEGs) were identified, of which 11,456 and 10,242 were up- and down-regulated, respectively, in comparative analysis. These DEGs were associated with crucial metabolic pathways, including hormone signaling, photosynthesis, lipid and carbohydrate metabolism, and cell wall biogenesis. Gene ontology (GO) examination revealed an enrichment of transcripts involved in salinity response. A total of 4257 differentially expressed GO terms were categorized into 64 functional groups; of which, GO terms like, integral component of membrane, organelle, and cellular anatomical entity were highly represented in tolerant genotypes under salt stress. Significant up-regulation of transcripts encoding potassium transporter family HAK/KUP proteins, MIP/aquaporin protein family, NADH dehydrogenase, pectinesterase, and PP2C family proteins occurred under salt stress. The tolerant lines (ICCV 10 and JG 11) engaged highly efficient machinery in response to elevated salt stress, especially for signal transduction, transport and influx of K+ ions, and osmotic homeostasis. The overall study highlights the role of potential candidate genes and their regulatory networks which can be utilized in breeding salt tolerant chickpea cultivars.

Chickpea (Cicer arietinum L.) is currently grown in over 50 countries representing a wide range of environments and cropping systems. Phenology (time to flowering, podding and maturity) is an important component of crop adaptation in these environments. Crop maturity ranges from 80 to 180 days depending on genotype, soil moisture, time of sowing, latitude and altitude. However, in at least two-thirds of the chickpea growing area, the available crop-growing season is short (90-120 days) due to risk of drought or temperature extremities at the end of season (pod filling stage of the crop). About 73% of the global chickpea area is in South and Southeast Asia where chickpea is largely grown rainfed in the post-rainy season on receding soil moisture and often experiences terminal drought and heat stresses. Early phenology is also important in autumn-sown rainfed crop in Mediterranean-type environments for escape from terminal drought, as in Australia; and in summer-grown crop in the temperate environments for escape from frost at the end of season, as in Canada. Early phenology is also needed for promotion of chickpea to rice-fallows and other late sown conditions of south Asia. Hence, development of early maturing cultivars is one of the major objectives in chickpea breeding programs of International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India and in several countries, including India, Myanmar, Bangladesh, Ethiopia, Australia and Canada. Several short-duration cultivars with resistance to fusarium wilt have been developed which have made significant impacts on enhancing chickpea area and production in central and southern India, Myanmar and Ethiopia. Efforts are being made to combine earliness with resistance to ascochyta blight and chilling tolerance for enhancing adaptation of chickpea to short-season Mediterranean regions and temperate environments. Early and extra-early cultivars are expected to play key role in expanding chickpea area in new niches where available crop growing season is short.

Photosynthesis is a key process for plant growth and development. However, exposure to supra-optimal temperatures disrupts the photosynthesis process through the inhibition and degradation of photosynthetic pigments, enzymes, and the photosynthetic apparatus, leading to a decrease in photosynthetic efficiency. Furthermore, supra-optimal temperatures induce premature leaf senescence, alterations in chloroplast structure, disruption of photosystems, and inhibition of electron transport. Heat stress also affects cyclic and non-cyclic electron flow and alters stomatal oscillations, which influence CO2 influx and water balance. Photosynthetic enzymes, such as Rubisco and sedoheptulose-1,7-bisphosphatase, are highly sensitive to heat stress. Understanding the physiological responses of photosynthesis to high-temperature stress is crucial for developing strategies to enhance plant resilience and mitigate the negative impacts of heat stress on crop productivity. This chapter discusses the physiological effects of high-temperature stress on photosynthesis in plants. The impact of heat stress on various photosynthetic components, including photosynthetic pigments, photosystems, electron transport systems, and enzymes involved in carbon assimilation is discussed.

Abstract Aims The mobility of phosphorus (P) depends on availability of water in soil; both are limited resources for crop production. We studied the mechanisms governing cross tolerance in the contrasting mungbean accessions for drought and low P stress. Methods Tolerant (IC333090 and IC507340) and sensitive (IC488526 and EC397142) mungbean accessions were grown in soil with treatments: control (sufficient P, irrigated), low P (no P, irrigated), drought (sufficient P, irrigation withheld), and combined stress (no P, irrigation withheld) as well as recovery. Results Drought reduced the relative water content and membrane stability index, affecting overall plant growth. Combined stress (low P and drought) significantly increased root growth, leaf area, and biomass in tolerant accessions, which was attributed to enhanced nutrient uptake and symbiotic N 2 -fixation. Combined stress also increased osmolyte concentration, antioxidative compounds, and scavenging activity of antioxidant enzymes in tolerant accessions while recovery from drought significantly reduced osmolyte concentration. Transcript abundance of candidate genes related to drought and low P was significantly higher in leaves of IC333090 than IC488526. Conversely, low-P-induced genes ( VrSPX1 , VrPHO1 , VrSQD1, VrPEPCase , and VrMDH ) in IC488526 were either downregulated or did not significantly change under combined stress. The drought recovery was better in IC333090 due to enhanced expression of stress-responsive genes. Conclusions Tolerant mungbean accession could be used as potential donor parents in breeding programs. Traits imparting cross tolerance to drought and low P stress may facilitate better varietal selection for increased crop productivity under low P, drought, and the combined stress.

Plastic production and its unplanned management and disposal, has been shown to pollute terrestrial, aquatic, and atmospheric environments. Petroleum-derived plastics do not decompose and tend to persist in the surrounding environment for longer time. Plastics can be ingested and accumulate into the tissues of both terrestrial and aquatic animals, which can impede their growth and development. Petrochemicals are the primary feedstocks for the manufacture of plastics. The plastic wastes can be retrieved back for conversion to value added petrochemicals including aromatic char, hydrogen, synthesis gas, and bio-crude oil using various technologies including thermochemical, catalytic conversion and chemolysis. This review focusses on technologies, opportunities, challenges and outlooks of retrieving back plastic wastes for conversion to value added petrochemicals. The review also explores both the technical and management approaches for conversion of plastic wastes to petrochemicals in regard to commercial feasibility, and economic and environmental sustainability. Further, this review work provides a detailed discussion on opportunities and challenges associated with recent thermochemical and catalytic conversion technologies adopted for retrieving plastic waste to fuels and chemicals. The review also recommends prospects for future research to improve the processes and cost-efficiency of promising technologies for conversion of plastic wastes to petrochemicals. It is envisioned that this review would overcomes the knowledge gaps on conversion technologies and further contribute in emerging sustainable approaches for exploiting plastic wastes for value-added products.

Abstract Chickpea crops are often exposed to a combination of drought, heat and salinity stresses during the reproductive stage. Previous efforts have largely focused on these stresses in isolation, such that we do not understand whether genotypes tolerant to one stress can withstand other stresses. Around 22–44 chickpea genotypes contrasting for tolerance to drought, salinity or heat in previous studies were exposed to terminal drought (TD, 3 experiments) and to salinity (SAL, 1 experiment). A priori stress tolerance to any of the listed stresses was generally reflected in drought and salinity tolerance in the present study. Thus, the drought‐, heat‐ and salt‐tolerant groups (DT, HT and ST) produced higher seed yield, had earlier phenology, higher harvest indices and seed yield transpiration efficiencies compared with sensitive groups (DS, HS and SS). However, tolerance did not select for prescriptive water use patterns. Despite our efforts to remove the confounding effects of phenology, 4–9 days variation in flowering time made a significant difference in productivity and differentiated tolerant from sensitive counterparts. In TD1, TD2 and SAL, all tolerant groups yielded similarly under stress conditions. This showed the existence of cross‐tolerance in chickpea where tolerant genotype selected for an individual stress can yield well under other stresses too.