The Ethiopian genetic center is considered to be one of the secondary centers of diversity for the common bean. This study was conducted to characterize the distribution of genetic diversity between ...and within ecological/geographical regions of Ethiopia. A germplasm sample of 116 landrace accessions was developed, which represented different common bean production ecologies and seed types common in the country. This sample was then analyzed with 24 simple sequence repeat (SSR) markers to assess the genetic diversity within and between common bean landraces, classifying them based on SSR clustering, and determining relationships between genetic and agroecological diversity. Representatives of both Andean and Mesoamerican gene pools were identified by STRUCTURE software analysis, as well as a high proportion of hybrid accessions as evidenced by a STRUCTURE K = 2 preset. At the optimum K = 5 preset value, mixed membership of Andean and Mesoamerican genotypes in some of the clusters was also seen, which supported previous findings. Cluster analyses, principal coordinate analysis, and analysis of molecular variance all indicated clustering of accessions from different collection sites, accompanied by high gene flow levels, highlighting the significant exchange of planting materials among farmers in different growing regions in the country. Values of allelic diversity were comparable to those reported in previous similar studies, showcasing the high genetic diversity in the landrace germplasm studied. Moreover, the distribution of genetic diversity across various bean-growing population groups in contrasting geographical/ecological population groups suggests elevated but underutilized potential of Ethiopian germplasm in common bean breeding. In summary, this study demonstrated the geographical, as well as gene pool diversity in common bean germplasm of Ethiopia. This substantial diversity, in turn, should be utilized in future common bean breeding and conservation endeavors in the nation.
Mechanosensitive (MS) ion channels are transmembrane proteins that open and close in response to mechanical forces produced by osmotic pressure, sound, touch and gravity. In plants, MS have an ...important role in different biological processes like gravity detection, maintenance of plastid shape and size, lateral root emergence, growth of pollen tube, and plant-pathogen interactions. In this study, homologous mechanosensitive channel of small conductance (MscS)-like gene family in common bean was identified. Nine Phaseolus vulgaris MscS-like (PvMSL) genes were found to be distributed on five chromosomes. A complete overview of PvMSL genes in common bean is presented, including gene structures, chromosome locations, phylogeny, protein motifs and expression pattern. Subcellular localization predictions of PvMSL family revealed their location to plasma and chloroplast membrane. Phylogenetic analysis of nine PvMSL proteins resulted in two main classes. The predicted gene structure, conserved motif, domain and presence of transmembrane regions in each PvMSL strongly supported their identity as members of MscS-like gene family. Four duplicate events of PvMSL genes were discovered in P. vulgaris chromosomes, and tandem and segmental duplication may cause the expansion of PvMSL genes. Furthermore, PvMSL genes displayed differential expression patterns in tissues and organs. This is the first step towards genome-wide analyses of MSL genes in common bean. Thus, the data obtained in this study provide resources to select candidate genes for future functional analyses that will help understand plant growth, development, and function of MSL gene family in P. vulgaris.
Background and Aims Drought is the principal constraint on world production of legume crops. There is considerable variability among genotypes in sensitivity of nitrogen fixation to drought, which ...has been related to accumulation of ureides in soybean. The aim of this study was to search for genotypic differences in drought sensitivity and ureide accumulation in common bean (Phaseolus vulgaris) germplasm that may be useful in the improvement of tolerance to water deficit in common bean. Methods Changes in response to water deficit of nitrogen fixation rates, ureide content and the expression and activity of key enzymes for ureide metabolism were measured in four P. vulgaris genotypes differing in drought tolerance. Key Results A variable degree of drought-induced nitrogen fixation inhibition was found among the bean genotypes. In addition to inhibition of nitrogen fixation, there was accumulation of ureides in stems and leaves of sensitive and tolerant genotypes, although this was higher in the leaves of the most sensitive ones. In contrast, there was no accumulation of ureides in the nodules or roots of stressed plants. In addition, the level of ureides in the most sensitive genotype increased after inhibition of nitrogen fixation, suggesting that ureides originate in vegetative tissues as a response to water stress, probably mediated by the induction of allantoinase. Conclusions Variability of drought-induced inhibition of nitrogen fixation among the P. vulgaris genotypes was accompanied by subsequent accumulation of ureides in stems and leaves, but not in nodules. The results indicate that shoot ureide accumulation after prolonged exposure to drought could not be the cause of inhibition of nitrogen fixation, as has been suggested in soybean. Instead, ureides seem to be produced as part of a general response to stress, and therefore higher accumulation might correspond to higher sensitivity to the stressful conditions.
To study the pattern of genetic diversity in 45 genotypes of common bean, 19 RAPD primers were used. Of 253 bands produced, 236 bands (94.22%) were polymorphic in which maximum number (20 polymorphic ...bands) were observed in the profiles of the primer OPB-07. Highest PIC value (0.79) was observed for the primers OPG-14 and OPE-1, whereas lowest PIC value (0.34) was recorded for the primer OPA-11 with an average PIC value of 0.54. Similarly, highest effective multiplex ratio value (0.11) was scored for the primers OPA-04 and OPG-6 and the lowest value (0.05) was recorded for the primer OPB-07. Primer OPG-14 and OPE-1 exhibited the highest marker index value (0.078) and the lowest value (0.024) was recorded for OPA-11. Pair-wise genetic similarity coefficients of genotypes varied from 0.56 to 0.92 with an average of 0.70 amongst 45 genotypes. The maximum similarity coefficient (0.92) was noticed between G-9 and G-8. Cluster analysis separated 45 genotypes into seven major clusters which were further grouped into various sub-clusters. Among these seven clusters, the maximum number of genotypes (12) were recorded in cluster I, while cluster VII formed a mono-genotypic cluster.
O uso de métodos estatísticos para avaliar o crescimento e produção das plantas é crucial para o avanço tecnológico do feijoeiro. A pesquisa teve por objetivo dimensionar a amostra para a estimação ...da média de caracteres avaliados em diferentes cultivares e condições hídricas. Os dados foram coletados quinzenalmente a partir de dois experimentos fatoriais 3 x 2 (3 cultivares: Triunfo, Garapiá e FC104; 2 regimes hídricos: irrigado, não irrigado). Foram coletados dezoito caracteres (estatura, diâmetro da haste, número de nós, comprimento da raiz, massa fresca e seca da parte aérea e raízes, temperatura foliar, área foliar, número de nódulos, massa fresca e seca dos nódulos, número de vagens, comprimento das vagens, grãos por vagem, grãos por planta e massa seca dos grãos). O tamanho da amostra foi determinado através do método de reamostragem boodstrap a partir de de 2.000 reamostragens, e foi definido pelo número de plantas a partir das quais o intervalo de confiança de 95% foi de 10% a 40% da estimativa média. Como resultado, o tamanho da amostra é diferente entre os caracteres e entre as cultivares e condições hídricas utilizadas. No intervalo de confiança de 95% com erro padrão de 40% da estimativa da média, para avaliar todos os caracteres analisados são necessárias 44 plantas dos caracteres de parte aérea, 132 plantas para os caracteres de raiz e 12 plantas nos caracteres produtivos. Para analisar os dezoito caracteres estudados são necessárias 132 plantas.
The Fusarium oxysporum species complex (FOSC) is a widely distributed group of fungi that includes both pathogenic and nonpathogenic isolates. In a previous study, isolates within the FOSC collected ...primarily from soybean were assessed for the presence of 12 fungal effector genes. Although none of the assayed genes was significantly associated with wilt symptoms on soybean, the secreted in xylem 6 (Six6) gene was present only in three isolates, which all produced high levels of vascular wilt on soybean. In the current study, a collection of F. oxysporum isolates from soybean roots and F. oxysporum f. sp. phaseoli isolates from common bean was screened for the presence of the Six6 gene. Interestingly, all isolates for which the Six6 amplicon was generated caused wilt symptoms on soybean, and two-thirds of the isolates showed high levels of aggressiveness, indicating a positive association between the presence of the effector gene Six6 and induction of wilt symptoms. The expression profile of the Six6 gene analyzed by quantitative reverse-transcription polymerase chain reaction revealed an enhanced expression for the isolates that caused more severe wilt symptoms on soybean, as established by the greenhouse assay. These findings suggest the suitability of the Six6 gene as a possible locus for pathogenicity-based molecular diagnostics across the various formae speciales.
High-pressure homogenization (HPH) can improve the functionalities of food proteins by forming soluble aggregates. This research aimed to determine the effects of thermal aggregation and ...high-pressure homogenization on the structural and emulsifying properties of kidney bean proteins. Results have shown that the soluble aggregates from heat-treated kidney bean proteins had markedly larger particle sizes and molecular weights than untreated proteins. This demonstrates that heat treatment could expose buried hydrophobic groups and free sulfhydryl groups, leading to SH/SS exchanges between protein molecules. Additionally, the viscosity, emulsifying activity, and emulsion stability of the thermally formed soluble aggregates increased substantially after heat treatment. HPH at a low pressure (30, 60 MPa) promoted the formation of disulfide bonds between molecules by hydrophobic interaction, leading to the formation of protein soluble aggregates. This increased the particle size, molecular weight, apparent viscosity, emulsion activity, and emulsion stability. HPH at high pressures (90, 120 MPa), on the other hand, has been shown to damage protein aggregates and break the disulfide bond, resulting in a decreased aggregate size, molecular weight, emulsion activity, and emulsion stability. Our findings showed that HPH at 60 MPa on thermally soluble aggregates of kidney bean protein could improve their physicochemical, structural, and emulsifying properties for potential beverage industrial applications.
Display omitted
•HPH of HKBPs influenced the structure of thermal aggregation denaturation resulting change in emulsifying properties.•HPH at low pressure could induce the formation of soluble aggregates proteins.•HPH at high pressure could cause disulfide bonds to be broken and disrupt the noncovalent interactions in protein aggregates.
The bean represents the main source of proteins for the low income populations, although the digestibility of those proteins is relatively low. Consequently, the programs of plant genetic breeding ...have been working on the search for new lines with higher protein levels. Thus, with the purpose of supplying information to the researchers, in this study, 21 bean (Phaseolus vulgaris L.) lines were analyzed for the centesimal and mineral composition, protein digestibility, phenolic compounds, and trypsin inhibitor. The entirely randomized experimental design was used with 21 treatments (lines) and three repetitions. All values were within the following ranges: 22.34 to 36.28 g crude protein/100 g dry matter (DM); 7.56 to 20.91 g neutral detergent fiber/100 g DM; 0.53 to 2.55 g fat/100 g DM and 2.97 to 4.87 g ashes/100 g DM. The levels of phosphorus, potassium, calcium, magnesium, and sulfur, in g/100 g DM, varied from 0.45 to 0.72; 1.51 to 2.48; 0.03 to 0.28; 0.18 to 0.34 and 0.28 to 0.45, respectively. Regarding copper, manganese, zinc and iron, the levels, in mg/kg DM, varied from 11.37 to 17.73; 14.93 to 28.90; 36.67 to 69.90 and 71.37 to 126.90, respectively. The in vitro protein digestibility varied from 18.03 to 48.32%. The levels of phenolic compounds varied from 0.28 to 1.08 mg acid tanic/100 g DM and the one of trypsin inhibitor from 59.93 to 151.07 trypsin inhibited units/mg DM. Among the lines with higher protein contents, "ESAL 569" (beige with brown stripe) presented the largest protein digestibility and considerable levels of minerals. "P-180" (beige with brown stripe) was one of the lines with higher crude protein contents and digestibilities, and also presented high levels for most of the minerals. No relation between protein digestibility and the contents of phenolic compounds or trypsin inhibitor was observed.
PDF
