Starch makes up 70% of the wheat grain, and is an important source of calories for humans, however, the overconsumption of wheat starch may contribute to nutrition-associated health problems. The challenge is to develop resistant starch including high amylose wheat varieties with health benefits. Adapting advance genomic approaches in EMS-induced mutant lines differing in amylose content, basic leucine zipper (bZIP) regulatory factors that may play role in controlling amylose biosynthesis were identified in wheat. bZIP transcription factors are key regulators of starch biosynthesis genes in rice and maize, but their role in regulating these genes in wheat is poorly understood. A genome-wide survey identified 370 wheat bZIPs, clustered in 11 groups, showing variations in amino acids composition and predicted physicochemical properties. Three approaches namely, whole transcriptome sequencing, qRT-PCR, and correlation analysis in contrasting high and low amylose mutants and their parent line identified 24 candidate bZIP (positive and negative regulators), suggesting bZIPs role in high amylose biosynthesis. bZIPs positive role in high amylose biosynthesis is not known. In silico interactome studies of candidate wheat bZIP homologs in Arabidopsis and rice identified their putative functional role. The identified bZIPs are involved in stress-related pathways, flower and seed development, and starch biosynthesis. An in-depth analysis of molecular mechanism of novel candidate bZIPs may help in raising and improving high amylose wheat varieties.

The phytopathogenic bacteria, Pseudomonas syringae pv. lapsa (P. syringae pv. lapsa) infects the staple food crop wheat. Metalloproteins play important roles in plant-pathogen interactions. Hence, the present work is aimed to predict and analyze the iron (Fe), zinc (Zn), and copper (Cu) binding proteins of P. syringae pv. lapsa which help in its growth, adaptation, survival and pathogenicity. A total of 232 Fe, 307 Zn, and 38 Cu-binding proteins have been identified. The functional annotation, subcellular localization and gene ontology enriched network analysis revealed their role in wide range of biological activities of the phytopathogen. Among the identified metalloproteins, a total of 29 Fe-binding, 31 Zn-binding, and 5 Cu-binding proteins were found to be secreted in nature. These putative secreted metalloproteins may perform diverse cellular and biological functions ranging from transport, response to oxidative stress, proteolysis, antimicrobial resistance, metabolic processes, protein folding and DNA repair. The observations obtained here may provide initial information required to draft new schemes to control microbial infections of staple food crops and will further help in developing sustainable agriculture.

Summary: Understanding the mechanisms of iron trafficking in plants is key to enhancing the nutritional quality of crops. Because it is difficult to image iron in transit, we currently have an incomplete picture of the route(s) of iron translocation in developing seeds and how the tissue‐specific distribution is established. We have used a novel approach, combining iron‐57 (⁵⁷Fe) isotope labelling and nanoscale secondary ion mass spectrometry (NanoSIMS), to visualize iron translocation between tissues and within cells in immature wheat grain, Triticum aestivum. This enabled us to track the main route of iron transport from maternal tissues to the embryo through the different cell types. Further evidence for this route was provided by genetically diverting iron into storage vacuoles, with confirmation provided by histological staining and transmission electron microscopy energy dispersive X‐ray spectroscopy (TEM‐EDS). Almost all iron in both control and transgenic grains was found in intracellular bodies, indicating symplastic rather than apoplastic transport. Furthermore, a new type of iron body, highly enriched in ⁵⁷Fe, was observed in aleurone cells and may represent iron being delivered to phytate globoids. Correlation of the ⁵⁷Fe enrichment profiles obtained by NanoSIMS with tissue‐specific gene expression provides an updated model of iron homeostasis in cereal grains with relevance for future biofortification strategies.

Purpose 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. Materials and methods 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. Results 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). Conclusion 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.

Potato (Solanum tuberosum L.) is an important food crop that is grown and consumed worldwide. The growth and productivity of this crop are severely affected by various abiotic stresses. Basic leucine zipper (bZIP) transcription factors (TFs) in plants are well known for their function during growth and development. However, systematic and in-depth identification and functional characterization of the bZIP gene family of potato is lacking. In the current study, we identified a total of 90 bZIPs (StbZIP) distributed on 12 linkage groups of potato. Based on the previous functional annotation and classification of bZIPs in Arabidopsis, wheat, and rice, a phylogenetic tree of potato bZIPs was constructed and genes were categorized into various functional groups (A to I, S, and U) as previously annotated in Arabidopsis thaliana. Analyses of the transcript sequence (RNA-seq) data led to identifying a total of 18 candidate StbZIPs [four in roots, eight in the tuber, six in mesocarp and endocarp] that were expressed in a tissue-specific manner. Differential expression analysis under the various abiotic conditions (salt, mannitol, water, and heat stress) and treatment with phytohormones (ABA, GA, IAA, and BAP) led to the identification of forty-two [thirteen under salt stress, two under mannitol stress, ten under water stress, and eighteen under heat stress], and eleven [eight and three StbZIPs upon treatment with ABA, and IAA, respectively] candidate StbZIPs, respectively. Using sequence information of candidate StbZIPs, a total of 22 SSR markers were also identified in this study. In conclusion, the genome-wide identification analysis coupled with RNA-Seq expression data led to identifying candidate StbZIPs, which are dysregulated, and may play a pivotal role under various abiotic stress conditions. This study will pave the way for future functional studies using forward and reverse genetics to improve abiotic stress tolerance in potato.