DND1-Silencing in Potato and Tomato Confers Resistance to Botrytis cinerea

Botrytis cinerea infects many crops including potato and tomato. Major genes for complete resistance to B. cinerea are not known, but a few quantitative trait loci (QTL) have been described in tomato. Previous studies have also proven that the loss of function of particular susceptibility (S) genes may provide resistance to B. cinerea in Arabidopsis.

Kaile Sun Wageningen University & Research used RNAi to silence the orthologs of Arabidopsis S genes DND1, DMR6, DMR1 and PMR4 in potato and the DND1 ortholog in tomato. The DND1-silenced potato and tomato plants showed significantly reduced B. cinerea leaf lesions as compared to control plants. Reduced lesions were also observed on the leaves of DMR6-silenced potato plants but only at 3 days after inoculation.

On the other hand, the DMR1 and PMR4-silenced potato transformants were still susceptible to B. cinerea as the control plants. Microscopic analysis in DND1-silenced potato and tomato leaves revealed that a significantly lower number of B. cinerea conidia remained attached to the leaf surface of the DND1-silenced potato and tomato plants. Moreover, the growth of the hyphae was also hindered.

Silencing of DND1 led to reduced susceptibility to Botrytis, which was found to be related to the impediment of conidial germination and attachment as well as hyphae growth. These provide new insights regarding the use of S genes in resistance breeding.

For more on this study, read the article in BMC Plant Biology.