Projects / Programmes
Response to water stress in common bean (Phaseolus vulgaris L.): proteomic analysis and QTL mapping
| Code |
Science |
Field |
Subfield |
| 4.03.01 |
Biotechnical sciences |
Plant production |
Agricultural plants |
| Code |
Science |
Field |
| B225 |
Biomedical sciences |
Plant genetics |
| Code |
Science |
Field |
| 4.04 |
Agricultural and Veterinary Sciences |
Agricultural biotechnology |
Common bean, Phaseolus vulgaris L., drought resistance, proteomic analysis, molecular markers, linkage map, disease resistance, serine proteases, QTL mapping, gene expression, breeding
Researchers (14)
Organisations (2)
Abstract
Periods of drought are frequent in Europe, including Slovenia, as a result of global climatic changes, and have a marked effect on agriculture. Common bean (Phaseolus vulgaris L.) is nutritionally very important legume plant that, at the same time, exhibits sensitivity to drought that affects its growth and yield. More than half of the world’s bean production is lost each year due to shortage of water. Certain plant species have developed mechanisms in adapting, to a greater or lesser extent, to drought, which are expressed on the molecular level by changes of gene expression and functional protein content, together with responses at physiological and morphological levels. Identifying such changes that differentiate between more tolerant and less tolerant varieties of common bean will provide the markers that are essential to characterize certain varieties as candidates for marker assisted selection in breeding for greater drought tolerance. Although some pointers have been established elsewhere and in our laboratories at the protein and gene levels, the basis of the response to drought in beans is still not sufficiently well characterized due to their genetic complexity and diverse, often ambiguous, phenotypic effects. The genome of common bean has not yet been sequenced and no proteome analyses connected to drought have been carried out. Our aim is to obtain a deeper insight into the molecular and morpho-physiological adaptation of common bean to drought. We therefore propose to investigate an existing family of drought tolerant (Tiber) and drought susceptible variety (Starozagorski čern), with 80 F8 recombinant inbred lines prepared in our laboratory, at the genomic and proteomic levels, alongside phenotypic observations.
The primary objectives of the proposed research on the protein level are (i) to establish the differences between plants subjected to water withdrawal and normally watered plants; (ii) to define the differences between parental lines subjected to drought stress; (iii) to identify proteins differentially expressed upon water deficit and (iv) to analyze changes at the level of glycoproteins; (v) to identify and characterize the proteolytic enzymes involved. The genetic approach will be focused on (i) identification of expressed sequences encoding for drought-stress related genes in a stress tolerant variety; ii) amplification and determination of molecular markers (SSR - Simple Sequence Repeats, EST-SSR Expressed Sequence Tags - SSR) and other drought stress gene-like sequences in order to assess their capacity to establish polymorphisms between parental lines; (iii) isolation and development of resistance gene analogue (RGA) markers linked to drought stress; (iv) testing molecular markers for segregation ratio in F8 generation (80 RILs) and identification of linkage groups, and finally (v) mapping different markers onto the common bean map.
The resulting integrated knowledge of genomic and proteomic processes during drought response will contribute to the basic understanding of drought tolerance, not only in bean but also in other plants, and will offer novel opportunities for bean management in different environments.
Significance for science
Understanding of response to external stimuli at the cellular level is of fundamental importance to the continuing existence of plants, particularly in the case of stress from adverse environmental conditions such as drought. The mechanism of response to drought stress in common bean is not well characterized. The reasons for slow improvement are genetic complexity coupled with the complex mechanism of water stress tolerance. A comprehensive study of drought response on morphological, physiological, biochemical and genetic level was carried out for two common bean varieties, drought tolerant variety Tiber and susceptible variety Starozagorski čern. Several morphological differences between varieties were identified, including those that differentiated the two varieties according to drought tolerance. A proteomic approach was used to identify drought responsive proteins in the two varieties. The majority of identified proteins were classified into functional categories that include photosynthesis, energy metabolism, stress, synthesis, proteolysis and protein folding. Interactions between identified proteins were demonstrated by bioinformatics analysis, enabling a more complete insight into biological pathways and molecular functions affected by drought stress. Several proteases were found to be involved in response to drought stress. Among them one serine endopeptidase and five aminopeptidases were characterised in more detail. They are active in leaves of both studied varieties, and the levels of activities are influenced by water deficit. The pattern of response is characteristic for the variety. Genetic map was constructed for population of 82 recombinant inbred lines, derived from the crossing Tiber x Starozagorski čern. Lines were monitored for morphological and physiological parameters and screened for 134 DNA markers which showed polymorphisms in parental lines. Linkage analysis distributed markers into 11 groups (LGs). The revealed marker distribution was combined with morphological data in Cartographer to obtain genetic map of quantitative traits (QTL). The strongest linkage was observed in LGs 1 and 9 between markers and QTL for number of days to flowering and one seed mass. The genetic and proteomic changes resulting from drought stress will be directly applicable in further studies of drought in different species of legume and other families. Such an integration of results contributes significantly to understanding of the plant response to abiotic stress that is by nature more complex physiologically but less well studied than biotic stress resistance in common bean. Informative molecular markers obtained by QTL analysis offer the potential to tag actual determinants and enable marker assisted selection (MAS) in common bean raising the efficiency of breeding programs for drought tolerance.
Significance for the country
In the strategy for and documentation on development of Slovene agriculture, the direction is defined as creating sustainable production of quality, affordable foodstuffs. Environmentally sound methods of production ensure preservation of soil fertility, protection of the environment, conservation of biotic diversity and preservation of traditional country land. This project is concerned with the quality and quantity of production of a nutritionally, economically and, thus socially important crop. In Slovenia, common bean production is second among vegetables (661 ha) only to that of cabbage (838 ha). Drought stress has an extremely serious effect on agriculture in general, but has also a damaging indirect effect on human communities (uncultivated land, forestification,..). Quality assortment, which should be adapted to local conditions and at the same time adapted to the taste of the local consumer, is the basis for competitive and sustainable production of any agricultural crop. Since the need for new, improved crop cultivars is always present, the simultaneous adaptation of assortment is necessary. For this reason genetic improvement of the quality and quantity of crop yield has to be a continual process. Genomic mapping of complex traits should help common bean breeders to devise more effective selection strategies. Incorporation of genomic information will provide an appropriate platform for studying traits of economic importance. It may also help breeders to better understand the basis of genotype – environment interactions. Only continual, long-term programmes of breeding and selection can enable the cultivation of new crop cultivars that are resistant to diseases and pests, thus reducing the need for phytopharmaceuticals and ensuring quality and high yields. Our results contribute to the recognition and active participation of Slovenia in international scientific research, specifically in the field of plant growth and agriculture. Several collaborations with foreign institutions have been established and functioning in the field of research on drought stress – bilateral scientific collaborations with Norway, Bulgaria and Serbia; a project with Norway in the frame of the Slovene scolarships fund. These not only strengthen the international quality of our scientific output by enabling access to state of the art methods and equipment, but also publically mark the activity of Slovene scientists, in publications and meetings, alongside scientists from other countries. Newly isolated gene, marker and protein sequences are being logged in international databases and made available for further characterization of diverse genomic studies by the international scientific community. All results are to be published in international journals and meetings. The research activities and results of the project are important in the education and stimulation of young researchers entering careers in fundamental and applied research. They, and those already involved in plant breeding in Slovenia, benefit from the fact that their training is in the context of internationally significant research in the fields of plant biology (physiology of response to drought stress, proteome and genetic analysis) and agriculture (breeding, development of tolerant varieties). In the field of drought stress a PhD student has been trained as a young researcher at the Agricultural Institute of Slovenia. The results will also be directly applicable for the management of the Phaseolus plant gene banks.
Most important scientific results
Annual report
2011,
2012,
2013,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2011,
2012,
2013,
final report,
complete report on dLib.si
