Plants are regularly exposed to biotic and abiotic stresses that adversely affect agricultural production. Omics has gained momentum in the last two decades, fueled by statistical methodologies, computational capabilities, mass spectrometry, nucleic-acid sequencing, and peptide-sequencing platforms. Functional genomics—especially metabolomics, transcriptomics, and proteomics—have contributed substantially to plant molecular responses to stress. Recent progress in reverse and forward genetics approaches have mediated high-throughput techniques for identifying stress-related genes. Furthermore, web-based genetic databases have mediated bioinformatics techniques for detecting families of stress-tolerant genes. Gene ontology (GO) databases provide information on the gene product’s functional features and help with the computational estimation of gene function. Functional omics data from multiple platforms are useful for positional cloning. Stress-tolerant plants have been engineered using stress response genes, regulatory networks, and pathways. The genome-editing tool, CRISPR-Cas9, reveals the functional features of several parts of the plant genome. Current developments in CRISPR, such as de novo meristem induction genome-engineering in dicots and temperature-tolerant LbCas12a/CRISPR, enable greater DNA insertion precision. This review discusses functional omics for molecular insight and CRISPR-Cas9-based validation of gene function in crop plants. Omics and CRISPR-Cas9 are expected to garner knowledge on molecular systems and gene function and stress-tolerant crop production.

Drought is a major abiotic stress that limits wheat productivity around the globe. Therefore, a two-year (2019 and 2020) study was conducted in the experimental area of the Department of Plant Breeding and Genetics, Faculty of Agriculture & Environment, The Islamia University of Bahawalpur, Pakistan to estimate the association of quantitative attributes under normal and drought stress conditions. Twenty-five wheat genotypes from different research institutes of Pakistan were selected. Experiment was conducted in a randomized complete block design (RCBD) under field conditions with three replicates each. Two irrigation treatments were used, i.e., E1 with full irrigation and E2 with irrigation withheld at tillering and anthesis stages according to Zadoks growth stage scale. Significant differences were observed in studied wheat genotypes under both conditions for all the traits. Correlation analysis revealed highest positive association (r = 0.924**) between grain yield and flag leaf area followed by thousand grain weight (r = 0.754**) under normal conditions while biological yield was highly correlated with grain yield (r = 0.890**) under drought stress. PCA showed that out of the 12 PCs, only four were significant having eigenvalues >1; accounting for 83.33% and 79.12% of the total variation under normal and drought stress conditions, respectively. Furthermore cluster heat map divided the genotypes into four clusters and revealed that the most tolerant genotypes (Barani-17, Chakwal-50 and Johar-2016) were fallen into cluster 2 depicting their genetic relatedness. Based on tolerance indices, genotypes G11 (Barani-17), G12 (Ehsan-16), and G13 (Dharabi-11) were drought tolerant and G4 (Benazir-13), G20 (Punjab-2011) were drought-sensitive.

Drought stress negatively affects the cotton production all over the world. The negative impact of drought varies for different species due to some morphological and root attributes that help some species to better stand under drought. But the extent of disturbance varies for different cotton species. To find out such variation, two cotton species (Gossypium hirsutumandGossypium arboreum) were studied under normal and drought conditions for 2 years. Two genotypes for each species were included, i.e. PC-1 and COMILLA (G. arboreum) and IUB-13 and IUB-65 (G. hirsutum). The experiment was laid out under a completely randomized design following factorial arrangement. Genotype × treatment × year interaction of cotton genotypes was studied for different root, morphological, physiological and fibre-related traits. Traits such as above ground dry biomass, above ground fresh biomass, chlorophyll contents, leaf area, seed cotton yield, sympodial branches/plant, fibre strength and ginning out-turn were higher inG. hirsutumgenotypes as compared toG. arboreumgenotypes. However less reduction under drought in all above mentioned traits was recorded forG. arboreum, thanG. hirsutum. Furthermore, root traits; primary root length, lateral root numbers, root fresh weight and root dry weight were enriched under drought condition inG. arboreumgenotypes than inG. hirsutumgenotypes, which is a clear manifestation of higher drought tolerance ability inG. arboreumgenotypes transferrable toG. hirsutumgenotypes through interspecific crossing or other means.

Emergence of unproductive vegetative shoots/flushes is considered to be a main cause of low yield, irregular bearing, and malformation of inflorescences in mango. Selected mango trees of the cultivars ‘Chaunsa’, ‘Dushehare’, and ‘Anwar Ratool’ growing in the subtropical region of Khanewal (30°18′0N, 71°56′0E), a district of Pakistan, were characterized as having excessive vegetative growth, erratic flowering, and fruiting with declining productivity due to malformation of inflorescences. Paclobutrazol soil drenching was evaluated as a method to suppress excessive vegetative growth and to increase the number of reproductive shoots even during the ‘off’ season. Different rates of paclobutrazol was applied at rates of (0, 2, 4, 6, 8, 10, and 12 g a.i.) in September through soil drenching. Results showed that soil drenching with paclobutrazol at the highest rates (12, 10, and 8 g a.i.) was significantly effective in suppressing vegetative growth, reducing the increase in canopy volume, and flush length as compared to control trees in all treated cultivars of mango. Statistically significant differences were recorded in treated trees as compared to control regarding the emergence of reproductive shoots, fruit setting, panicle length, fruit drop, intensity of emergence of malformed panicles, and yield. Response of selected cultivars of mango to paclobutrazol was statistically different regarding various vegetative and reproductive growth characteristics. Paclobutrazol was more useful in ‘Seasonal Chaunsa’ as compared to ‘Dushehare’ and ‘Anwar Ratool’ for improving various vegetative and reproductive parameters studied in this research.