Testing promising genes for pre-selection for drought tolerance in potato
Potato (Solanum tuberosum L.) is sensitive to drought mainly due to its fibrous root system. With the global climate change, the yield loss in potato cultivation caused by drought is expected to reach 30% over the following years. A breeding approach to increase the tolerance of potato to drought stress requires a long time, quite laborious and expensive, mainly due to limitations in a controlled drought treatment in the field conditions, high heterozygosity nature of the plant and genotype × environment (G×E) interaction. A pre-selection in the laboratory for the promising drought tolerant lines is a requirement to disentangle these obstacles. However, the complexity and multigenic nature of the drought stress response mechanism restrains the identification of molecular markers to be used in pre-selection purposes. Here, we used a novel approach and investigated the possibility of using the gene expression under controlled conditions for pre-selection of drought tolerant potato cultivars. For this purpose, we analyzed next generation sequencing results of 'Unica' (tolerant) and 'Russet Burbank' (sensitive) potato cultivars to 23 days of drought treatment and selected genes with contrasting expression levels under stress/control conditions. Control expression levels of five promising genes [plastidial pyruvate kinase 4 (XM_006360110.1), cryptochrome-2 (XM_006354425.1), cytosolic L-ascorbate peroxidase 1 (XM_006366063.1), early responsive to dehydration 15 (HG975443.1) and GAST1 (XM_006338257.1)] were tested by RT-PCR approach in a different set of potato genotypes with defined drought tolerance index evaluated in an independent field drought experiment to test their efficiency in pre-selection of drought tolerance potential. Although the results indicated the potential of plastidial pyruvate kinase 4 for detecting tolerant potato genotypes, it appears that the differentiation of tolerance and sensitivity potential by a simple RT-PCR approach still requires investigation of a large set of genes together.
Jameel, S., Demirel, U. and Öztürk Gökçe, Z.N. (2019). Testing promising genes for pre-selection for drought tolerance in potato. Acta Hortic. 1251, 49-56
potato, Solanum tuberosum L., drought stress, RT-PCR, breeding