Enhancing stress tolerance in legumes

CH Foyer1, JW Cooper1, MH Wilson1 and K Kunert2

  1. Centre for Plant Sciences, Faculty of Biology, University of Leeds, Leeds, LS2 9JT, UK
  2. Forestry and Agricultural Biotechnology Institute, Department Plant Science, University of Pretoria, Hillcrest, Pretoria 0002, South Africa

The Food and Agriculture Organization of the United Nations has been nominated to facilitate the implementation of the 2016 Year of the Pulses with the purpose of increasing public awareness of the nutritional benefits of grain legumes, as well as for sustainable food production. As a protein staple in the diet of many of the world’s poorest particularly in Africa, legumes are nature’s gemstones because they are protein-packed and nutritious. The science and policy community have not yet ceased the gauntlet of encouraging intensified research and related breeding to improve pulse crops (see Nature Plants 2, doi:10.1038/NPlants.2016.112). Increasing the global production of pulses, would provide a sustainable solution to future food and protein security. In this talk, I will describe some of our studies seeking to understand the physiological and molecular basis for drought and low temperature tolerance in soybean (Glycine max), which is highly sensitive to dark chilling temperatures (0–15 °C) and faba bean (Vicia faba L.) which is chilling tolerant. Constitutive expression of the rice cysteine protease inhibitor, oryzacystatin-I (OCI), in soybean led to increased drought and chilling tolerance. Since the agronomic improvement of legumes, such as faba bean is currently impeded by a lack of genomic resources, I will describe our recent efforts to generate new sequence information based on Illumina short-read sequencing of DNA extracted from faba bean embryos. This yielded 406,000,000 100bp paired end reads, which were assembled into 361,000,000 contiguous sequences. Sequences were aligned to published data from faba bean and other legume species. Repetitive elements, such as the gypsy- and copia-type retrotransposons were identified. Moreover, previously-identified Single Nucleotide Polymorphism-based linkage markers were extended in sequence length by 300-1500bp across the 6 faba bean chromosomes. A high level of homology was found in the coding genes of both the chloroplast and the mitochondrial genomes. These findings will be discussed within the context of improving food security in sub-Saharan Africa.