For PC2, there were significant effects of BABA treatment (P?=?0��002), cultivar (P?=?0��03), time (P?=?0��001) and infection (P?=?0��02). The interaction between cultivar, treatment and infection was also significant (P?=?0��04). The results from the analysis of individual phenols in Bintje and Ovatio are illustrated in Figure?7. Two days after treatment with BABA, there was a significant increase in the amount of arbutin in both Bintje (P?=?0��02) and Ovatio (P?=?0��004). In Ovatio, the concentration of the three chlorogenic acid derivatives (CQA1, CQA2 and CQA3) and the unknown compounds U1 and U2 increased significantly after treatment with BABA (CQA1: P?<?0��0001; CQA2: P?=?0��003; CQA3: P?=?0��005; U1: P?=?0��01; U2: P?=?0��004). The infection had no significant effect on the concentration of any of the phenols in Ovatio, whereas a small increase in the arbutin concentration was seen in Bintje <a href="http://www.selleck.cn/products/gsk126.html
">GSK 126 (P?=?0��01) and U4 (P?=?0��03). Several of the phenol peaks increased significantly with time in Bintje (arbutin: P?=?0��003; U2: P?=?0��006; U4: P?=?0��04) and in Ovatio (CQA1: P?<?0��0001; CQA2: P?<?0��0001; <a href="http://www.selleckchem.com/products/BI-2536.html
">Selleckchem BI2536 CQA3: P?=?0��002; rutin: P?<?0��0001). A significant time-dependent reduction was found only for CQA1 (P?=?0��02) in Bintje and U3 in Ovatio (P?=?0��007). The rutin concentration was significantly higher in Bintje than in Ovatio (P?<?0��0001). Analysis of the effect of BABA on the interaction between P.?infestans and two potato cultivars exhibiting different levels of resistance revealed that BABA led to direct activation of defence responses in a cultivar-specific manner, in contrast to the priming effect reported in Arabidopsis (Slaughter et?al., 2012). This demonstrates the importance of performing studies not only in the plant�Cpathosystem, but also in the cultivar of interest. There were no significant differences in colonization by P.?infestans of the two cultivars studied here, whereas Liljeroth et?al. (2010) found significant differences between the same two cultivars regarding lesion size after P.?infestans infection. This discrepancy can be explained by the use of different analytical methods and timings in the two studies. Here, colonization was quantified by qPCR at 96?hpi, while in the previous study lesion size was quantified by measurement of lesion <a href="http://www.selleckchem.com/products/Cyclopamine.html
">Selleck Cyclopamine diameter at 7?days post-inoculation (dpi). At 3?dpi, P.?infestans had just penetrated the leaves and small brown lesions had begun to appear at the site of inoculation. At this time point, no differences in lesion size were visible macroscopically. However, once the infection had been established, the lesions expanded more rapidly in Bintje than in Ovatio (Liljeroth et?al., 2010). Staining with trypan blue revealed that BABA treatment induced HR-like lesions in the leaves, regardless of whether they were subsequently infected with P.?infestans or not. The HR-like response was visible macroscopically as early as 2?days after treatment with 10?mm BABA.