Genetic enhancement of chickpea varieties for improved drought resistance and prediction of yield performance using APSIM model under soil bed glasshouse condition

S Das Bhowmik1, A Cheng1, H Long1, M Hoang1, Y Chauhan2, B Williams1, TJ Higgins3 and SM Mundree1

  1. CTCB Gardens Point Campus Queensland University of Technology QLD 4001
  2. Department of Agriculture and Fisheries, PO Box 23, Kingaroy, Qld 4610, Australia
  3. CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601 Australia

Chickpea is an important nutritious pulse crop of high demand globally. Due to lower than expected yields in the Indian subcontinent as a result of climatic changes, Australia has an unprecedented opportunity to significantly increase chickpea production and export. While we have some natural advantages, increasing chickpea production also has some inherent challenges. Increasing climate variability and change including excessive heat and water deficit as well as the increasing incidence of pests/diseases are major risk factors that affect the industry. Forecasters predict that by 2070 there will be 40 % more months of drought in eastern Australia and conditions will be worse in a high-emissions scenario. Upon abiotic and biotic stress, plant cells accumulate high levels of misfolded proteins that can lead to cell death. To mitigate stress levels plants have evolved cytoprotective genes that help maintain proper folding of proteins and reduce stress-induced death. The BAG genes are a family of multifunctional stress protective co-chaperones that facilitate protein folding and are conserved in mammals as well as plants. Here we describe the development and assessment of elite GM chickpea varieties expressing BAG genes isolated from Arabidopsis thaliana and the Australian resurrection plant Tripogon loliiformis. An efficient regeneration and transformation system was established using Agrobacterium””mediated transformation of half embryonic axis of chickpea (variety Hattrick). Using this system we achieved transformation efficiencies of up to 3 %. In glasshouse trials, transgenic chickpea lines maintained two-fold higher yields compared to non-transgenic Hattrick controls under both mild and severe drought stress. In addition to increased yields, upon stress the transgenic plants produced higher quality grain with reduced tiger striping and increased size. Our results indicate that expression of co-chaperones is a suitable method for the development of elite chickpea varieties that are drought tolerant. The performance of the APSIM model on the basis of average yield was satisfactory with simulated yield. Overall, the results suggest that performance of chickpea genotypes in terms of phenological development and yield under stress conditions could be simulated reasonably well in the glasshouse using the APSIM model. Furthermore, the development of an efficient transformation system provides tremendous potential for the introduction of additional elite traits into chickpea in the future.