Abstract
Barley (Hordeum vulgare) has importance for both as livestock feed and as part of the human food chain. The climate crisis underscores the need for improvement of crop productivity. The iSMARTBAR project will contribute to these aims through the identification of genes allowing the tuning of leaf chlorophyll content, the modification of canopy architecture, and the improved tolerance of water stress. Candidate genes will be validated by gene editing and allelic diversity will also be explored by means of a wheat TILLING platform, cutting edge protein structural modeling to develop novel variant prioritization approaches. Summary of results of iSMARTBAR, PRIN2022 PNRR The iSMARTBAR project aimed to identify novel genes and alleles controlling canopy architecture, photosynthetic efficiency and drought-responsive traits in barley to support the development of climate-resilient “smart canopy” ideotypes. The project combined large-scale mutant screening, genetic mapping, whole-genome sequencing, bioinformatics, candidate gene validation and dissemination activities, successfully achieving all planned milestones and deliverables. A major outcome of the project was the systematic phenotypic screening of the TILLMore barley mutant collection, followed by genetic and molecular characterization of selected mutants displaying altered leaf architecture or photosynthetic performance. These efforts led to the mapping of several novel loci, the identification of strong candidate genes and causal mutations, the establishment of new bioinformatics tools for variant prioritization, and the implementation of transformation and gene-editing pipelines that will accelerate future functional validation and breeding applications.
Results achieved
by UNIMI (Research Unit 1) UNIMI coordinated the project and led the identification and characterization of mutants affecting leaf angle and photosynthesis. Optimized phenotyping protocols enabled the identification of five erect-leaf mutants (TM64, TM629, TM949, TM3630 and TM4340) and four pale-green mutants (TM31, TM199, TM5236 and TM5702). Whole-genome sequencing and mapping-by-sequencing were successfully applied to identify genomic regions controlling these traits. Among the most important scientific achievements, UNIMI identified HvCLV1/HvFON1 as the candidate gene controlling leaf erectness in mutant HT-5061, demonstrating that a premature stop mutation co-segregates with the phenotype and validating its role through independent mutant alleles and field phenotyping. The project also identified HCF101 as the strongest candidate gene underlying the pale-green mutant HT-793, linking the mutation to impaired photosystem assembly and altered photosynthetic performance through molecular, physiological and biochemical characterization. Additional candidate genes were identified for TM31 and TM949 using newly developed variant prioritization pipelines integrating barley pangenome resources. UNIMI further developed an efficient computational workflow for mapping-by-sequencing and variant prioritization, established barley transformation and CRISPR editing protocols, performed complementation and gene validation experiments, and generated valuable genetic resources for future functional analyses. These activities resulted in robust candidate gene validation and provided powerful tools that extend well beyond the duration of the project.Results achieved
by UNIBO (Research Unit 2) UNIBO led the large-scale field screening of the TILLMore population, evaluating approximately 3,600 mutant lines and identifying novel mutants affecting leaf width, leaf angle, chlorophyll accumulation and stomatal development. In particular, UNIBO discovered broad-leaf mutant TM2544 together with several mutants showing significantly altered stomatal density, providing new genetic resources for studies of leaf development and gas exchange. Using mapping-by-sequencing, UNIBO demonstrated that the broad-leaf phenotype of TM2544 is caused by a mutation in the known BLF1 gene and validated this conclusion through allelism tests. In parallel, the group genetically mapped the rolled-leaf mutant TM349 and erect-leaf mutant TM3493, narrowing the responsible genomic intervals and identifying several high-confidence candidate genes for each mutant based on sequence variation, expression profiles and predicted protein function. UNIBO also established a transformation platform for Cas9-mediated genome editing in barley, designed guide RNAs for candidate gene validation, initiated complementary validation strategies using wheat orthologues, and generated important genomic resources that will support future functional characterization of leaf architecture genes. Furthermore, UNIBO contributed substantially to dissemination through dedicated workshops, public engagement activities and presentations at national and international conferences. Overall, iSMARTBAR successfully generated novel knowledge on the genetic control of canopy architecture and photosynthetic traits in barley, delivering mapped mutants, validated candidate genes, advanced bioinformatics resources, transformation and genome-editing platforms, and extensive dissemination outputs. These results provide a strong foundation for future functional genomics studies and breeding strategies aimed at developing high-yielding and climate-resilient barley and other Triticeae crops.Project details
Unibo Team Leader: Silvio Salvi
Unibo involved Department/s:
Dipartimento di Scienze e Tecnologie Agro-Alimentari
Coordinator:
Università degli Studi di MILANO(Italy)
Total Unibo Contribution: Euro (EUR) 94.598,00
Project Duration in months: 24
Start Date:
30/11/2023
End Date:
28/02/2026
