Biology subjects

Khazaei, H.

Publications and source records attributed to Khazaei, H..

10 recordsLinked to original sources

bioRxiv2025

Linking stomatal function with photosynthetic light reactions and stress response in faba bean

Faba bean (Vicia faba L.) is a key protein crop, but its cultivation and yield stability are hindered by a number of environmental stresses. Stomata regulate gas exchange between the plant and atmosphere, playing a central role in photosynthesis and mediating plant responses to a wide range of environmental stressors. This study aimed to investigate variations in leaf temperature as a proxy for stomatal function and photosynthetic regulations in faba bean, and to examine the response of this crop to short-term acute ozone (O3) exposure stress. Here, we used a high-throughput plant phenotyping (HTPP) platform to screen 196 faba bean genotypes for photosynthetic and stomatal function under controlled conditions. A subset of extreme genotypes, identified based on relative leaf tempreture from the initial screening, was exposed to a 450 ppb O3 treatment. Our results revealed strong positive relationship between photosynthetic efficiency and relative leaf temperature. A three-fold difference in relative leaf temperature was observed among genotypes. The O3 treatment caused signicantly less damage in genotypes with higher leaf temperature compared to those with lower leaf temperature (p<0.001). By combining a HTPP platform with elevated O3 stress treatment, we identified faba bean genotypes with contrasting stomatal responses to the O3 exposure. Our results advance understanding of the regulation mechanisms of photosynthetic light reactions and the role of stomatal function in modulating faba bean responses to environmental stressors.

plant biology↗

bioRxiv2025

Teaching good agronomic practices to strengthen pigeon pea cultivation and value chains through farmer-to-farmer education in Zambia

Farmer field schools (FFSs) are transformative, participatory approaches to adult agricultural education that effectively promote farmers learning and capacity building and empower farming communities with practical knowledge. Here, we present a case study of FFS in the Katete district, Eastern province of Zambia, focused on good pigeon pea agronomic practices and the value chain. Three FFSs were established, focusing on a variety of trials, bio-pesticides, and a pigeon pea-specific rhizobial inoculant. Extreme weather conditions, an underdeveloped pigeon pea seed value chain, and a poor seed system hindered the implementation of the FFSs. To strengthen the pigeon pea seed value chain, a seed dehuller is now available to farmers. Our results highlight the importance of the design, implementation, monitoring, and evaluation of the FFSs. Pigeon pea FFSs will support crop and food diversification, improve soil fertility and sustainable agriculture, and may increase household income.

scientific communication and education↗

bioRxiv2022

The giant diploid faba genome unlocks variation in a global protein crop

Increasing the proportion of locally produced plant protein in currently meat-rich diets could substantially reduce greenhouse gas emission and loss of biodiversity. However, plant protein production is hampered by the lack of a cool-season legume equivalent to soybean in agronomic value. Faba bean (Vicia faba L.) has a high yield potential and is well-suited for cultivation in temperate regions, but genomic resources are scarce. Here, we report a high-quality chromosome-scale assembly of the faba bean genome and show that it has grown to a massive 13 Gb in size through an imbalance between the rates of amplification and elimination of retrotransposons and satellite repeats. Genes and recombination events are evenly dispersed across chromosomes and the gene space is remarkably compact considering the genome size, though with significant copy number variation driven by tandem duplication. Demonstrating practical application of the genome sequence, we develop a targeted genotyping assay and use high-resolution genome-wide association (GWA) analysis to dissect the genetic basis of hilum colour. The resources presented constitute a genomics-based breeding platform for faba bean, enabling breeders and geneticists to accelerate improvement of sustainable protein production across Mediterranean, subtropical, and northern temperate agro-ecological zones.

plant biology↗

bioRxiv2022

Dissection of genotype-by-environment interaction and simultaneous selection for grain yield and stability in faba bean (Vicia faba L.)

Increasing faba bean production is indispensable to supply the growing demand for plant-based protein on the global scale. A thorough understanding of genotype (G) x environment (E) interaction (GEI) patterns is critical to developing high-yielding varieties with wider adaptation. Thirteen faba bean genotypes were evaluated in 15 environments during 2019-2020 in western Canada to estimate their yield stability using different stability statistics. The combined analysis of variance and additive main effects and multiplicative interaction (AMMI) analysis revealed that G, E, and GEI effects were highly significant (P<0.001), indicating differential responses of the genotypes across the environments, enabling the stability analysis. The result of the model comparison found the best linear unbiased prediction (BLUP) to outperform AMMI models. The BLUP-based biplot of the weighted average of absolute scores (WAASB) stability and mean grain yield identified AO1155 (Navi), 1089-1-2, 1310-5, DL Tesoro, and 1239-1 as high-yielding and stable genotypes. The correlation analysis revealed that most of the stability parameters had a strong association with grain yield and with each other, indicating that they should be used in combination with one another to select genotypes with high yield. Overall, the WAASB superiority index (WAASBY) and the average sum of ranks of all stability statistics identified the same genotypes in terms of high yielding and stability, and genotype AO1155 is considered the most stable and highest yielding among the tested genotypes. Genotypes with stable yields across environments would be beneficial for faba bean genetic improvement programs globally. Core IdeasO_LIStability analysis was estimated using 13 faba bean genotypes over 15 site-years. C_LIO_LIThe different stability methods described genotypic performance in different ways. C_LIO_LIThe majority of stability models showed a strong rank correlation with grain yield. C_LIO_LIAMMI and BLUP analyses revealed a highly significant GxE interaction, with BLUP outperforming AMMI. C_LIO_LIOverall, the employed stability statistics identified AO1155 as the highest yielding and most stable genotype. C_LI

plant biology↗

bioRxiv2022

Leaf trichome diversity, acylsugar concentration, and their relationships to leaf area in Solanum galapagense

Glandular trichomes are physical and chemical barriers used by some tomato wild relatives to confer resistance against insect pests and diseases transmitted by them. Solanum galapagense has been identified as one of the potential sources of insect pest resistance. The present study aimed to examine the trichome diversity and acylsugar concentration of 26 accessions of S. galapagense along with one cultivated tomato (S. lycopersicum) and one cherry tomato (S. l. cerasiforme) cultivar. The results revealed large genetic variation among S. galapagense accessions for all studied traits. The S. galapagense accessions had significantly higher trichome types IV on the adaxial and abaxial surfaces of the leaf and greater acylsugar concentration but smaller leaflet area than cultivated tomato. The selected cherry tomato line represents greater trichome type IV and acylsugar than other groups. The acylsugar concentration was positively associated with trichome type IV but negatively associated with trichome type V on both leaf surfaces. Leaflet area was negatively associated with trichome IV density and acylsugar concentration. Analysis of DNA markers revealed the presence of two previously identified whitefly-resistance alleles in S. galapagense accessions. This study will support breeding programs aiming to improve insect pest resistance in tomato cultivars using crop wild relatives.

plant biology↗

bioRxiv2022

Genetic analysis of global faba bean germplasm maps agronomic traits and identifies strong selection signatures for geographical origin

Faba bean (Vicia faba L.) is a high-protein grain legume crop with great potential for further cultivation. However, little is known about the genetics underlying trait diversity. In this study, we use 21,345 high-quality SNP markers to genetically characterise 2,678 faba bean genotypes. We perform genome-wide association studies of key agronomic traits using a Seven-parent-MAGIC population and detect 238 significant marker-trait associations linked to 12 traits of agronomic importance, with 65 of these being stable across multiple environments. Using a non-redundant diversity panel of 685 accessions from 52 countries, we identify 3 subpopulations differentiated by geographical origin and 33 genomic regions subject to strong diversifying selection between subpopulations. We find that SNP markers associated with the differentiation of northern and southern accessions were able to explain a significant proportion of agronomic trait variance in the Seven-parent-MAGIC population, suggesting that some of these traits have played an important role in breeding. Altogether, our findings point to genomic regions associated with important agronomic traits and selection in faba bean, which can be used for breeding purposes. Key MessageWe identified marker-trait associations for key faba bean agronomic traits and genomic signatures of selection within a global germplasm collection.

genetics↗

bioRxiv2021

Genomic regions associated with chocolate spot (Botrytis fabae Sard.) resistance in fababean (Vicia faba L.)

Chocolate spot (CS), caused by Botrytis fabae Sard., is an important threat to global faba bean production. Growing resistant faba bean cultivars is, therefore, paramount to preventing yield loss. To date, there have been no reported quantitative trait loci (QTLs) associated with CS resistance in faba bean. The objective of this study was to identify genomic regions associated with CS resistance using a recombinant inbred line (RIL) population derived from resistant accession ILB 938. A total of 165 RILs from the cross Melodie/2 x ILB 938/2 were genotyped and evaluated for CS reactions under replicated controlled climate conditions. QTL analysis identified five loci contributing to CS resistance on faba bean chromosomes 1 and 6, accounting for 5.0-23.4% of the total phenotypic variance. The sequences of SNP markers linked to resistance QTLs on chromosome 1 that have the largest effects encode multiple classes of putative disease and/or defense-related genes. The results of this study not only provide insight into disease-resistance QTLs, but also can be used as potential targets for marker-assisted breeding in faba bean genetic improvement for CS resistance. Key messageQTL mapping identified key genomic regions associated with chocolate spot resistance on faba bean chromosomes 1 and 6, which may serve as novel genetic tools to develop disease-resistant faba bean cultivars.

genomics↗

bioRxiv2021

Machine Learning Speeding Up the Development of Portfolio of New Crop Varieties to Adapt to and Mitigate Climate Change

Climate change poses serious challenges to achieving food security in a time of a need to produce more food to keep up with the worlds increasing demand for food. There is an urgent need to speed up the development of new high yielding varieties with traits of adaptation and mitigation to climate change. Mathematical approaches, including ML approaches, have been used to search for such traits, leading to unprecedented results as some of the traits, including heat traits that have been long sought-for, have been found within a short period of time.

plant biology↗

bioRxiv2021

An advanced lentil backcross population developed from a cross between Lens culinaris x L. ervoides for future disease resistance and genomic studies

Genetically accessible variation to some of the abiotic and biotic stresses are limited in the cultivated lentil (Lens culinaris Medik.) germplasm. Introgression of novel alleles from its wild relative species might be required for enhancing the genetic improvement of the crop. L. ervoides, one of the wild relatives of lentil, is a proven source of disease resistance for the crop. Here we introduce a lentil advanced backcross population (LABC-01) developed in cultivar CDC Redberry background, based on L. ervoides alleles derived from an interspecific recombinant inbred population, LR-59-81. Two-hundred and seventeen individuals of the LABC-01 population at BC2F3:4 generation were screened for the race 0 of anthracnose (Colletotrichum lentis) and stemphylium blight (Stemphylium botryosum) under controlled conditions. The population showed significant variations for both diseases and transfer of resistance alleles into the elite cultivar was evident. It also segregated for other traits such as days to flowering, seed coat colour, seed coat pattern and flower colour. Overall, we showed that LABC-01 population can be used in breeding programs worldwide to improve disease resistance and will be available as a valuable genetic resource for future genetic analysis of desired loci introgressed from L. ervoides.

plant biology↗

bioRxiv2020

VC1 catalyzes a key step in the biosynthesis of vicine from GTP in faba bean

Faba bean is a widely adapted and high-yielding legume cultivated for its protein-rich seeds1. However, the seeds accumulate the anti-nutritional pyrimidine glucosides vicine and convicine, which can cause haemolytic anaemia--favism--in the 400 million individuals genetically predisposed by a deficiency in glucose-6-phosphate dehydrogenase2. Here, we identify the first enzyme associated with vicine and convicine biosynthesis, which we name VC1. We show that VC1 co-locates with the major QTL for vicine and convicine content and that the expression of VC1 correlates highly with vicine content across tissues. We also show that low-vicine varieties express a version of VC1 carrying a small, frame-shift insertion, and that overexpression of wild-type VC1 leads to an increase in vicine levels. VC1 encodes a functional GTP cyclohydrolase II, an enzyme normally involved in riboflavin biosynthesis from the purine GTP. Through feeding studies, we demonstrate that GTP is a precursor of vicine both in faba bean and in the distantly related plant bitter gourd. Our results reveal an unexpected biosynthetic origin for vicine and convicine and pave the way for the development of faba bean cultivars that are free from these anti-nutrients, providing a safe and sustainable source of dietary protein.

biochemistry↗