Rhizoctonia solani is a soil-borne fungus causing sheath blight disease in cereal crops including rice. Genetic resistance to sheath blight disease in cereal crops is not well understood in most of the host(s). Aside from this, a comparative study on the different hosts at the biochemical and proteomic level upon R. solani infection was not reported earlier. Here, we performed proteomic based analysis and studied defense pathways among cultivated rice (cv. Pusa Basmati-1), wild rice accession (Oryza grandiglumis), and barley (cv. NDB-1445) after inoculation with R. solani. Increased levels of phenol, peroxidase, and β-1, 3-glucanase were observed in infected tissue as compared to the control in all of the hosts. Wild rice accession O. grandiglumis showed a higher level of biochemical signals than barley cv. NDB 1445 and cultivated rice cv. Pusa Basmati-1. Using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS), differently expressed proteins were also studied in control and after inoculation with R. solani. Wild rice accession O. grandiglumis induced a cysteine protease inhibitor and zinc finger proteins, which have defense functions and resistance against fungal pathogens. On the other hand, barley cv. NDB-1445 and cultivated rice cv. Pusa Basmati-1 mainly induce energy metabolism-related proteins/signals after inoculation with R. solani in comparison to wild rice accession O. grandiglumis. The present comprehensive study of R. solani interaction using three hosts, namely, Pusa Basmati-1 (cultivated rice), O. grandiglumis (wild rice), and NDB-1445 (barley) would interpret wider possibilities in the dissection of the protein(s) induced during the infection process. These proteins may further be correlated to the gene(s) and other related molecular tools that will help for the marker-assisted breeding and/or gene editing for this distressing disease among the major cereal crops.

High temperature causes several biological changes in wheat and results in yield reduction. Use of DNA marker linked to heat resistance/tolerance attributes accelerates selection and expedites breeding for heat tolerance. In this study, heat-tolerant wheat var. Halna and heat-susceptible wheat var. K9006 were selected as donor and recipient, respectively, after phenotyping. In the F2 population, heat tolerant and susceptible Lines were bulked for the bulk segregant analysis. Parental polymorphism was studied by 32 RAPD primers, of which only six primers showed polymorphism between parents and used for the confirmation of F1crosses. The 10 tolerant and 10 susceptible F2 plants (F1 (K 9006 × Halna) were bulked and the tolerant bulk showing maximum membrane stability index (53.48%) and chlorophyll content (2.16 mg/g) were used for the molecular study. The RAPD primer (OPE 09) segregated susceptible and tolerant bulks and an unique band of 700 bp was observed in the tolerant parent (var. Halna) and the tolerant bulk was cloned and sequenced. A SCAR marker was developed from the cloned bands, and a primer pair was designed. The designed SCAR marker was successfully validated on the randomly selected heat-susceptible and heat-tolerant wheat varieties. The obtained sequence from the cloned unique bands of the tolerant bulk can be further utilized via bioinformatics tools. Further physicochemical, secondary structure prediction, transmembrane domain, tertiary structure prediction, active site prediction, and molecular docking were performed to analyze and elucidate the cloned sequence. The findings indicate that the identified sequence might be related to a specific biochemical pathway involving tolerance to heat stress in wheat.

With a long-term objective of making cultivated variety Sesamum indicum tolerant to phyllody disease, phytoplasma specific cDNA clone was isolated by a differential display from S. alatum which is tolerant to phyllody disease. For this, total RNAs were isolated from the leaves of S. indicum, S. alatum and S. alatum on which S. indicum having phyllody had been grafted and differential display was performed. Comparison of cDNA products obtained at various stages of grafting allowed picking fifteen putative cDNA clones. To confirm that which of these cDNA fragments are truly unique to the target tissues, the differential display experiment was repeated and reverse northern was performed. Four cDNA clones were finally selected, reamplified and subsequently cloned in pMOS vector. One of the cDNA clones also showed hybridization signal in S. indicum which was affected with phyllody but not in the healthy S. indicum. This cDNA clone was not only constitutive and defense related but also phytoplasma specific. This partial cDNA clone (AP13 + C1) obtained after the differential display was used as a probe for isolation of the full-length cDNA library from S. alatum. By colony hybridization, a homogenous cDNA clone of 1.2 kb was isolated. Nucleotide sequence translation and their BLAST search revealed 99.82% homology to putative lipoamide dehydrogenase. According to the created phylogenetic tree, it was inferred that the Poaceae (Oryza sativa & Oryza brachyantha) were grouped with Pedaliaceae (S. alatum) and formed monophyletic clade. Further, its physicochemical analysis revealed that the protein was somewhat acidic, hydrophobic, thermostable and stable. Genetic manipulation of this gene may thus pave the way to make cultivated sesamum phyllody resistant.