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Mitogen-activated protein kinase kinase kinases (MAPKKKs) are important components of MAPK cascades, which have different functions during developmental processes and stress responses. To date, there has been no systematic investigation of this gene family in the diploid cotton Gossypium arboreum L. In this study, a genome-wide survey was performed that identified 78 MAPKKK genes in G. arboreum. Phylogenetic analysis classified these genes into three subgroups: 14 belonged to ZIK, 20 to MEKK, and 44 to Raf. Chromosome location, phylogeny, and the conserved protein motifs of the MAPKKK gene family in G. arboreum were analyzed. The MAPKKK genes had a scattered genomic distribution across 13 chromosomes. The members in the same subfamily shared similar conserved motifs. The MAPKKK expression patterns were analyzed in mature leaves, stems, roots, and at different ovule developmental stages, as well as under salt and drought stresses. Transcriptome analysis showed that 76 MAPKKK genes had different transcript accumulation patterns in the tested tissues and 38 MAPKKK genes were differentially expressed in response to salt and drought stresses. These results lay the foundation for understanding the complex mechanisms behind MAPKKK-mediated developmental processes and abiotic stress-signaling transduction pathways in cotton. Key words: MAPKKK, Gossypium arboreum, ovule, salt stress, drought stress. Les MAP kinase kinase kinases (MAPKKK) sont d'importantes composantes des cascades de MAPK, lesquelles jouent divers roles au cours du developpement et de la reponse aux stress. A ce jour, aucune etude systematique de cette famille de genes n'a ete realisee chez le cotonnier diploide, Gossypium arboreum L. Dans ce travail, une analyse complete du genome a ete faite et a permis d'identifier 78 genes codant pour des MAPKKKK chez le G. arboreum. Une analyse phylogenetique a permis de classifier ces genes en trois sous-groupes dont 14 appartenaient aux ZIK, 20 aux MEK et 44 aux Raf. La position chromosomique, la phylogenie et les motifs conserves pour ces membres de la famille des MAPKKK chez le G. arboreum ont ete analyses. Les genes codant des MAPKKK etaient distribues sur 13 chromosomes. Les membres d'une meme sous-famille partageaient des motifs conserves semblables. L'expression des MAPKKK a ete analysee chez les feuilles matures, les tiges, les racines et a differents stades de developpement des ovules, aussi bien que suite a des stress de salinite et de secheresse. Ces analyses du transcriptome ont revele que 76 genes MAPKKK presentaient des niveaux differents d'accumulation de ces transcrits dans les tissus examines et que 38 de ces genes etaient exprimes differemment en reponse au stress salin ou de secheresse. Ces resultats fournissent une assise pour la comprehension des mecanismes par lesquels les MAPKKK contribuent aux processus developpementaux et aux sentiers de signalisation en reponse aux stress abiotiques chez le cotonnier. [Traduit par la Redaction] Mots-cles : MAPKKK, Gossypium arboreum, ovule, stress salin, stress de secheresse., Introduction The mitogen-activated protein kinase (MAPK) cascade is a universal protein kinase signaling transduction module, and plays a vital role in connecting receptors/sensors to extracellular and nuclear responses in eukaryotes [...]

Earliness and plant height traits are key targets in lentil (Lens culinaris Medikus) breeding and are quantitatively controlled. Recombinant inbred lines (RILs) are useful in genetic mapping studies of quantitative traits. The objectives of this study are to develop a genetic map and identify genome regions associated with earliness and plant height using RILs derived from a cross between 'Eston' x PI320937. Number of days to flower and plant height at flowering were collected at two Saskatchewan locations, Saskatoon and Floral, in 2004. Two hundred and seven amplified fragment length polymorphism (AFLP), simple sequence repeat (SSRs), and random amplified polymorphic DNA (RAPD) markers were used to genotype 94 RILs. The markers were ordered into 12 linkage groups (LGs) with a total length of 1868 cM. The average density of markers was 8.9 cM. The AFLP markers were distributed throughout the genome, whereas RAPD and SSR markers were located on LG4 to LG9 only. A resistance gene to anthracnose [caused by Colletotrichum truncatum (Schwein.) Andrus & W.D. Moore] and a quantitative trait locus (QTL) to ascochyta blight (caused by Ascochyta lentis Vassilievsky) were mapped previously on LG6. Quantitative trait loci affecting earliness and plant height were identified on LG1, LG2, LG4, LG5, LG9, and LG12 at Saskatoon and Floral evaluation locations and explained 37 to 46% and 31 to 40% of the total variation, respectively. Earliness QTLs that were consistently expressed at both locations were concentrated on LG4 and LG12, and markers flanking these QTL regions could be good candidates for marker-assisted selection.

Abstract: Ascochyta blight, caused by the fungus Ascochyta rabiei (Pass.) Lab., is one of the most devastating diseases of chickpea (Cicer arietinum L.) worldwide. Research was conducted to map genetic [...]

The ability for plant tissue to regenerate following in vitro culture is highly dependent on the genotype. The inheritance of somatic embryogenesis In orchardgrass (Dactylis glomerata L.; 2n = 4x = 28) was studied using one embryogenic genotype (Embryogen-P) and random plants from two nonembryogenic populations, Jay and OSG-13. Individual plants from [F.sub.1] (Embryogen-P X Jay), [F.sub.2], [BC.sub.1], and test cross ([F.sub.1] X OSG-13) matings were evaluated for somatic embryogenesis. Leaf bases were cultured in the dark on SH medium containing 30 µM dicamba (3,6-dichloro-o-anisic acid) at 25 ° C for 4 wk. Qualitative differences of callus quality ranging from undesirable watery and gelatinous to desirable compact, firm, and friable were observed In all segregating populations. The percentage of plants initiating a firm and friable callus was significantly (P [is less than] 0.05) correlated to the frequency of embryogenic plants. The segregation ratios observed across all matings indicated that the ability to form somatic embryos from cultures derived from leaf base explants of orchardgrass was conditioned by two independent dominant genes with complementary effects. The genotype of Embryogen-P was simplex/simplex. The simple model of inheritance and the dominance of the character simplifies development of cultivars with improved in vitro response that would facilitate the application of biotechnological techniques In this species., Regeneration from in vitro culture is a key step for the application of many biotechnology techniques such as genetic. transformation. Somatic embryos have been obtained from many tissues of orchardgrass [...]

Copyright of Genome is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Genome is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to evaluate a set of recombinant inbred lines (RILs) for agronomic and physiological traits under drought conditions and to locate quantitative trait loci (QTL) associated with them. This study used a RIL population derived from a cross between drought tolerant (ILC 588) and susceptible (ILC 3279) genotypes. The population consisting of 155 RILs was grown under drought conditions in the field at Tel Hadya, Syria, in 2006 and 2007 and at Breda, Syria, in 2007. A genetic map consisting of eight linkage groups was developed using 97 simple sequence repeat (SSR) markers. The results revealed that high harvest index (HI), early flowering, and early maturity were the important attributes contributing to higher grain yield under drought. Higher stomatal conductance (gs) and cooler canopies (canopy temperature minus air temperature ETc-Ta]) can also lead to better performance under drought conditions. Quantitative trait locus analysis identified 15 genomic regions significantly associated with various traits affecting drought tolerance in chickpea. Important QTL detected in this study included two QTL for HI explaining 38% of the total phenotypic variability of the trait, four QTL for flowering explaining 45%, and three QTL for maturity explaining 52% on a cumulative basis. Three QTL for gs and six QTL for Tc-Ta also detected explained 7 to 15% phenotypic variability individually. Two QTL (Q3-1 and Q1-1) on linkage group 3 (LG3) and LG1 showed effects on many traits related to drought. Hence, these regions can be further explored in future drought studies. [ABSTRACT FROM AUTHOR]

Random amplified polymorphic DNA, simple sequence repeat, and inter-simple sequence repeat markers were used to estimate the genetic relations among 65 pea varieties (Pisum sativum L.) and 21 accessions from wild Pisum subspecies (subsp.) abyssinicum, asiaticum, elatius, transcaucasicum, and var. arvense. Fifty-one of these varieties are currently available for growers in western Canada. Nei and Li's genetic similarity (GS) estimates calculated using the marker data showed that pair-wise comparison values among the 65 varieties ranged from 0.34 to 1.00. GS analysis on varieties grouped according to their originating breeding programs demonstrated that different levels of diversity were maintained at different breeding programs. Unweighted pair-group method arithmetic average cluster analysis and principal coordinate analysis on the marker-based GS grouped the cultivated varieties separately from the wild accessions. The majority of the food and feed varieties were grouped separately from the silage and specialty varieties, regardless of the originating breeding programs. The analysis also revealed some genetically distinct varieties such as Croma, CDC Handel, 1096M-8, and CDC Acer. The relations among the cultivated varieties, as revealed by molecular-marker-based GS, were not significantly correlated with those based on the agronomic characters, suggesting that the 2 systems give different estimates of genetic relations among the varieties. However, on a smaller scale, a consistent subcluster of genotypes was identified on the basis of agronomic characters and their marker-based GS. Furthermore, a number of variety-specific markers were identified in the current study, which could be useful for variety identification. Breeding strategies to maintain or enhance the genetic diversity of future varieties are proposed. [ABSTRACT FROM AUTHOR]

Improving the seed protein concentration (SPC) of pea ( Pisum sativum L.) has turned into an important breeding objective because of the consumer demand for plant-based protein and demand from protein fractionation industries. To support the marker-assisted selection (MAS) of SPC towards accelerated breeding of improved cultivars, we have explored two diverse recombinant inbred line (RIL) populations to identify the quantitative trait loci (QTLs) associated with SPC. The two RIL populations, MP 1918 × P0540-91 (PR-30) and Ballet × Cameor (PR-31), were derived from crosses between moderate SPC × high SPC accessions. A total of 166 and 159 RILs of PR-30 and PR-31, respectively, were genotyped using an Axiom® 90K SNP array and 13.2K SNP arrays, respectively. The RILs were phenotyped in replicated trials in two and three locations of Saskatchewan, Canada in 2020 and 2021, respectively, for agronomic assessment and SPC. Using composite interval mapping, we identified three QTLs associated with SPC in PR-30 and five QTLs in PR-31, with the LOD value ranging from 3.0 to 11.0. A majority of these QTLs were unique to these populations compared to the previously known QTLs for SPC. The QTL SPC-Ps-5.1 overlapped with the earlier reported SPC associated QTL PC-QTL-3. Three QTLs, SPC-Ps-4.2 , SPC-Ps-5.1 , and SPC-Ps-7.2 with LOD scores of 7.2, 7.9, and 11.3, and which explained 14.5%, 11.6%, and 11.3% of the phenotypic variance, respectively, can be used for marker-assisted breeding to increase SPC in peas. Eight QTLs associated with the grain yield were identified with LOD scores ranging from 3.1 to 8.2. Two sets of QTLs, SPC-Ps-2.1 and GY-Ps-2.1 , and SPC-Ps-5.1 and GY-Ps-5.3 , shared the QTL/peak regions. Each set of QTLs contributed to either SPC or grain yield depending on which parent the QTL region is derived from, thus confirming that breeding for SPC should take into consideration the effects on grain yield., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Gali, Jha, Tar’an, Burstin, Aubert, Bing, Arganosa and Warkentin.)

Chickpea is an economically and nutritionally important grain legume globally, however, cold stress has adverse effects on its growth. In cold countries, like Canada where the growing season is short, having cold stress-tolerant varieties is crucial. Crop wild relatives of chickpea, especially Cicer reticulatum , can survive in suboptimal environments and are an important resource for crop improvement. In this study, we explored the performance of eleven C. reticulatum wild accessions and two chickpea cultivars, CDC Leader and CDC Consul, together with a cold sensitive check ILC533 under freezing stress. Freezing tolerance was scored based on a 1-9 scale. The wild relatives, particularly Kesen&#95;075 and CudiA&#95;152, had higher frost tolerance compared to the cultivars, which all died after frost treatment. We completed transcriptome analysis via mRNA sequencing to assess changes in gene expression in response to freezing stress and identified 6,184 differentially expressed genes (DEGs) in CDC Consul, and 7,842 DEGs in Kesen&#95;075. GO (gene ontology) analysis of the DEGs revealed that those related to stress responses, endogenous and external stimuli responses, secondary metabolite processes, and photosynthesis were significantly over-represented in CDC Consul, while genes related to endogenous stimulus responses and photosynthesis were significantly over-represented in Kesen&#95;075. These results are consistent with Kesen&#95;075 being more tolerant to freezing stress than CDC Consul. Moreover, our data revealed that the expression of CBF pathway-related genes was impacted during freezing conditions in Kesen&#95;075, and expression of these genes is believed to alleviate the damage caused by freezing stress. We identified genomic regions associated with tolerance to freezing stress in an F2 population derived from a cross between CDC Consul and Kesen&#95;075 using QTL-seq analysis. Eight QTLs (P<0.05) on chromosomes Ca3, Ca4, Ca6, Ca7, Ca8, and two QTLs (P<0.01) on chromosomes Ca4 and Ca8, were associated with tolerance to freezing stress. Interestingly, 58 DEGs co-located within these QTLs. To our knowledge, this is the first study to explore the transcriptome and QTLs associated with freezing tolerance in wild relatives of chickpea under controlled conditions. Altogether, these findings provide comprehensive information that aids in understanding the molecular mechanism of chickpea adaptation to freezing stress and further provides functional candidate genes that can assist in breeding of freezing-stress tolerant varieties., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Kalve, House and Tar’an.)

The molecular mechanism involved in chickpea ( Cicer arietinum L.) resistance to the necrotrophic fungal pathogen Ascochyta rabiei is not well documented. A. rabiei infection can cause severe damage in chickpea, resulting in significant economic losses. Understanding the resistance mechanism against ascochyta blight can help to define strategies to develop resistant cultivars. In this study, differentially expressed genes from two partially resistant cultivars (CDC Corinne and CDC Luna) and a susceptible cultivar (ICCV 96029) to ascochyta blight were identified in the early stages (24, 48 and 72 h) of A. rabiei infection using RNA-seq. Altogether, 3073 genes were differentially expressed in response to A. rabiei infection across different time points and cultivars. A larger number of differentially expressed genes (DEGs) were found in CDC Corinne and CDC Luna than in ICCV 96029. Various transcription factors including ERF, WRKY, bHLH and MYB were differentially expressed in response to A. rabiei infection. Genes involved in pathogen detection and immune signalings such as receptor-like kinases (RLKs), Leucine-Rich Repeat (LRR)-RLKs, and genes associated with the post-infection defence response were differentially expressed among the cultivars. GO functional enrichment and pathway analysis of the DEGs suggested that the biological processes such as metabolic process, response to stimulus and catalytic activity were overrepresented in both resistant and susceptible chickpea cultivars. The expression patterns of eight randomly selected genes revealed by RNA-seq were confirmed by quantitative PCR (qPCR) analysis. The results provide insights into the complex molecular mechanism of the chickpea defence in response to the A. rabiei infection.

The availability of wild chickpea ( Cicer reticulatum L.) accessions has the potential to be used for the improvement of important traits in cultivated chickpeas. The main objectives of this study were to evaluate the phenotypic and genetic variations of chickpea progeny derived from interspecific crosses between C. arietinum and C. reticulatum, and to establish the association between single nucleotide polymorphism (SNP) markers and a series of important agronomic traits in chickpea. A total of 486 lines derived from interspecific crosses between C. arietinum (CDC Leader) and 20 accessions of C. reticulatum were evaluated at different locations in Saskatchewan, Canada in 2017 and 2018. Significant variations were observed for seed weight per plant, number of seeds per plant, thousand seed weight, and plant biomass. Path coefficient analysis showed significant positive direct effects of the number of seeds per plant, thousand seed weight, and biomass on the total seed weight. Cluster analysis based on the agronomic traits generated six groups that allowed the identification of potential heterotic groups within the interspecific lines for yield improvement and resistance to ascochyta blight disease. Genotyping of the 381 interspecific lines using a modified genotyping by sequencing (tGBS) generated a total of 14,591 SNPs. Neighbour-joining cluster analysis using the SNP data grouped the lines into 20 clusters. The genome wide association analysis identified 51 SNPs that had significant associations with different traits. Several candidate genes associated with early flowering and yield components were identified. The candidate genes and the significant SNP markers associated with different traits have a potential to aid the trait introgression in the breeding program.

Chickpea ( Cicer arietinum L.) is a staple food in many developing countries where iron (Fe) deficiency often occurs in their population. The crop is a good source of protein, vitamins, and micronutrients. Fe biofortification in chickpea can be part of long-term strategy to enhance Fe intake in human diet to help to alleviate Fe deficiency. To develop cultivars with high Fe concentration in seeds, understanding the mechanisms of absorption and translocation of Fe into the seeds is critical. An experiment was conducted using a hydroponic system to evaluate Fe accumulation in seeds and other organs at different growth stages of selected genotypes of cultivated and wild relatives of chickpea. Plants were grown in media with Fe zero and Fe added conditions. Six chickpea genotypes were grown and harvested at six different growth stages: V3, V10, R2, R5, R6, and RH for analysis of Fe concentration in roots, stems, leaves, and seeds. The relative expression of genes related to Fe-metabolism including FRO2 , IRT1 , NRAMP3 , V1T1 , YSL1 , FER3 , GCN2 , and WEE1 was analyzed. The results showed that the highest and lowest accumulation of Fe throughout the plant growth stages were found in the roots and stems, respectively. Results of gene expression analysis confirmed that the FRO2 and IRT1 were involved in Fe uptake in chickpeas and expressed more in roots under Fe added condition. All transporter genes: NRAMP3 , V1T1 , YSL1 along with storage gene FER3 showed higher expression in leaves. In contrast, candidate gene WEE1 for Fe metabolism expressed more in roots under Fe affluent condition; however, GCN2 showed over-expression in roots under Fe zero condition. Current finding will contribute to better understanding of Fe translocation and metabolism in chickpea. This knowledge can further be used to develop chickpea varieties with high Fe in seeds., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Jahan, Kalve, Belak, Eskiw and Tar’an.)