Frost Tolerance

In Australia and other cereal growing regions with a Mediterranean climate, frost events at flowering can cause sterility, leading to extreme yield reductions, as well as damaged seeds. In Victoria and South Australia alone, frost causes annual losses in wheat and barley productivity of around $95.8m and $33.6m, respectively. Severe winter temperatures experienced in some northern hemisphere regions can also kill plants at the hardier vegetative stage. Periods of cold but non-freezing temperatures can also reduce fertility.

Objectives

1. Isolate genes determining natural frost and cold tolerance.
2. Characterize the molecular and physiological mechanisms of frost tolerance.
3. Identify strategies for genetic engineering of frost tolerance in cereals.
4. Generate markers and knowledge to assist conventional frost tolerance breeding.

Experimental Strategy

The Waite barley breeding group identified regions of the 2H and 5H barley chromosomes determining varietal differences in frost tolerance. Fine-mapping and cloning of the underlying genes is being aided by the conservation in gene content and order between barley and the sequenced rice genome. A state-of-the-art frost simulation chamber housed in the Australian Genome Research Facility (AGRF) on campus enables evaluation of frost tolerance levels. Yeast 1-hybrid screens and expression analyses are being employed to identify transcription factors controlling cold and frost responses. Genes are being functionally evaluated using barley and wheat transformation.

Current research activities

• Fine mapping and cloning of barley frost tolerance genes from the 2H and 5H chromosomes.
• Evaluation of how flowering time loci effect the expression of nearby frost tolerance genes in barley.
• Molecular characterization of frost tolerance gene candidates.
• Identification of transcription factors involved in the cold response in wheat.
• Physiological characterization of barley frost tolerance using the frost simulation chamber.
• Using transgenic wheat and barley plants to functionally evaluate frost tolerance gene candidates, such as particular CBF/DREB and bHLH type transcription factors.

Contacts

 Selected Publications

• Chen A, Gusta LV, Brûlé-Babel A, Leach R, Baumann U, Fincher GB, Collins NC (2009). Varietal and chromosome 2H locus-specific frost tolerance in reproductive tissues of barley (Hordeum vulgare L.) detected using a frost simulation chamber. Theoretical and Applied Genetics 119: 685-694.
• Chen A, Baumann U, Fincher GB, Collins NC (2009). Flt-2L, a locus in barley controlling flowering time, spike density, and plant height. Functional and Integrative Genomics 9: 243-254.
• Chen A, Reinheimer J, Brûlé-Babel A, Baumann U, Pallotta M, Fincher GB, Collins NC (2009). Genes and traits associated with chromosome 2H and 5H regions controlling sensitivity of reproductive tissues to frost in barley. Theoretical and Applied Genetics 118: 1465-1476.
• Chen A, Brûlé-Babel A, Baumann U, Collins NC (2009). Structure-function analysis of the barley genome: the gene-rich region of chromosome 2HL. Functional and Integrative Genomics 9: 67-79.
• Collins NC, Tardieu F, Tuberosa R (2008) Quantitative trait loci and crop performance under abiotic stress: Where do we stand? Plant Physiology 147: 469-486.

Prospective students can read about ACPFG Frost Tolerance projects here