Sorghum is one of the most important food and feed cereal crops and has been gaining industrial importance in recent years for its biofuel, nutraceutical and antioxidant values. A genetic profile variation study was undertaken for the accumulation of phytochemicals in 61 diverse sorghum accessions differing in their growth habitat and grain color through non-targeted Gas Chromatography–Mass Spectrometry (GC-MS/MS) analysis. Mass Spectrometry–Data Independent AnaLysis (MS-DIAL) and MetaboAnalyst identified 221 metabolites belonging to 27 different phytochemicals. Tropical and temperate sorghums were distinct in their metabolic profiles with minimum overlaps, and 51 different metabolites were crucial in differentiating the two groups. Temperate sorghums had the ability to accumulate more of phenolic acids, phytosterols, flavonoids, carotenoids, and tropical sorghums for stress-related amino acids, sugars and fatty acids. Grain-color-based Partial Least Square–Discriminant Analysis (PLS-DA) analysis identified 94 Variable Importance in Projections (VIP) metabolites containing majority of flavonoids, phenylpropanoids and phytosterols. This study identified two sorghum lines (IS 7748 and IS 14861) with rich amounts of antioxidants (catechins and epicatechins) belonging to the group of condensed tannins that otherwise do not accumulate commonly in sorghum. Out of 13 metabolic pathways identified, flavonoid biosynthesis showed the highest expression. This study provided new opportunities for developing biofortified sorghum with enhanced nutraceutical and therapeutics through molecular breeding and metabolic engineering.

Stomata regulates conductance, transpiration and photosynthetic traits in plants. Increased stomatal density may contribute to enhanced water loss and thereby help improve the transpirational cooling process and mitigate the high temperature-induced yield losses. However, genetic manipulation of stomatal traits through conventional breeding still remains a challenge due to problems involved in phenotyping and the lack of suitable genetic materials. Recent advances in functional genomics in rice identified major effect genes determining stomatal traits, including its number and size. Widespread applications of CRISPR/Cas9 in creating targeted mutations paved the way for fine tuning the stomatal traits for enhancing climate resilience in crops. In the current study, attempts were made to create novel alleles of OsEPF1 (Epidermal Patterning Factor), a negative regulator of stomatal frequency/density in a popular rice variety, ASD 16, using the CRISPR/Cas9 approach. Evaluation of 17 T0 progenies identified varying mutations (seven multiallelic, seven biallelic and three monoallelic mutations). T0 mutant lines showed a 3.7–44.3% increase in the stomatal density, and all the mutations were successfully inherited into the T1 generation. Evaluation of T1 progenies through sequencing identified three homozygous mutants for one bp insertion. Overall, T1 plants showed 54–95% increased stomatal density. The homozygous T1 lines (# E1-1-4, # E1-1-9 and # E1-1-11) showed significant increase in the stomatal conductance (60–65%), photosynthetic rate (14–31%) and the transpiration rate (58–62%) compared to the nontransgenic ASD 16. Results demonstrated that the genetic alterations in OsEPF1 altered the stomatal density, stomatal conductance and photosynthetic efficiency in rice. Further experiments are needed to associate this technology with canopy cooling and high temperature tolerance.

Aim: The present study aimed at measuring the genetic diversity of a set of 219 sorghum accessions differing in their grain colour. Methodology: About 219 diverse sorghum lines differing in their grain colour were obtained from National Bureau of Plant Genetics Resources (NBPGR), New Delhi and genotyped using 17 SSR markers. Polymorphism information content (PIC) and allele frequency were determined using PowerMarker V3.25. Clustering and factorial analysis were performed using DARwin 6.0. GenAlex version 6.5 was used to perform Principal Coordinates Analysis (PCoA) and AMOVA. Diversity analysis was performed by using Darwin. Results: Genotyping of 219 sorghum accessions using 17 SSR markers produced a total of 399 alleles with an average PIC value of 0.85 and gene diversity of 0.87. Highest allele frequency was observed for the marker, Xtxp 265 whereas highest major allele frequency was observed in 196 accessions for the marker, Xtxp 278. Diversity analysis divided the 219 accessions into three clusters (1, 2 and 3) and genotypes belonging to same geographical origin were found to be clustered together. Interpretation: SSR marker based genetic diversity analysis grouped 219 sorghum accessions into three clusters. Grouping and clustering of accessions was mostly based on the geographical origins with some exceptions which may be due to cross hybridisation of accessions between countries paving a way for cross gene flow.

This genome-wide association studies (GWAS) used a subset of 96 diverse sorghum accessions, constructed from a large collection of 219 accessions for mining novel genetic loci linked to major agronomic and physiological traits including root. The subset yielded 43,452 high quality single nucleotide polymorphic (SNP) markers exhibiting high allelic diversity. Population stratification showed distinct separation between caudatum and durra races. Linkage disequilibrium (LD) decay was rapidly declining with increasing physical distance across all chromosomes. The initial 50% LD decay was ~ 5Kb and background level was within or below ~ 80Kb. Plant height and grain color identified significant SNPs co-localized with dwarfing dw2 locus and chalcone synthase, respectively, indicating the representativeness of the population and reliability of methods. AP2-like ethylene-responsive transcription factor and gibberellin receptor GID1L2 affecting single plant yield and biomass respectively were identified. The study detected novel genetic loci linked to drought avoidance traits viz., Leucine rich repeat family protein (root biomass and root architecture), AP2 domain containing protein (intrinsic water use efficiency) and serine/threonine protein kinase (abaxial stomatal complex total area). This study justified that the constructed subset of diverse sorghums can be used as a panel for mapping other key traits to accelerate molecular breeding in sorghum.

Inthisunpredictableclimaticscenario,increasingcropproductivityunderlow water availability is the foremost challenge. The crops are further seriously affected,andtheyieldsaredrasticallyreducedduetoelevatedtemperature, greenhousegases,andhumidityduringthewater stressperiod.Toensure food security in the coming decades, scientists have summoned to increase thehigh-quality foodwiththeseclimaticvagaries. Thoughseveralagronomic and management strategies were proposed to mitigate the water stress, genetic improvementof cropswithimproveddroughttoleranceis the simple, sustainable and affordable option. Nevertheless, identification and molecular understandingoftheappropriatebreedingtraits thatcanalleviatetheimpact of water stress on crop plants are the trickiest part ofthis strategy. Sorghum (Sorghum bicolor L.)is gaining its importance in water stress tolerance plant breeding, as it has several clearly defined drought-tolerant component traits that promote productivity underlow water environments. The genomics and phenomics information generated in S. bicolor would immensely help breeding plants resilientto thechallenges of a water scarcity. This paper describes themolecularmechanismsofdroughttoleranceusing sorghum bicoloras amodel and howthis information canbeextrapolatedto breed better cultivars in other crops.