Val F, Desender S, Bernard K, Potin P, Hamelin G, Andrivon D
INRA, Agrocampus Rennes, UMR1099 BiO3P (Biology of Organisms and Populations applied to Plant Protection), F-35000 Rennes, France.
Phytopathology. 2008 Jun;98(6):653-8. doi: 10.1094/PHYTO-98-6-0653.
Priming of defense reactions by an elicitor results in an enhanced ability of the plant to respond to subsequent pathogen challenges. We previously showed that application of lipopolysaccharides (LPS) to potato cell suspensions causes apoplastic acidification, but does not stimulate lipoxygenase (LOX) activity. Here, we tested the ability of various elicitors to prime and elicit defense reactions in potato cell suspensions. Adding 20 microg ml(1) LPS, laminarin, harpin N, or a concentrated culture filtrate (CCF) of Phytophthora infestans to cell cultures 18 h before a second elicitation with LPS did not alter the intensity of apoplastic acidification compared with a single LPS application. Conversely, high concentrations (200 or 400 microg ml(1)) of LPS, laminarin, and harpin N activated LOX in cells pretreated with 1 microg ml(1) CCF, but not in cells pretreated with LPS, laminarin, or harpin N. LOX response was maximal in pretreated cells of potato cv. Bintje when the second elicitation occurred 18 to 24 h after CCF application. These results showed that LOX activation is primed in potato cells by CCF, but not by LPS, harpin N, or laminarin. Finally, bioassays showed a slightly greater reduction of rot weight in half tubers treated with CCF followed by LPS before inoculation with Pectobacterium atrosepticum than in half tubers treated with either preparation alone, indicating a priming effect of CCF on both LOX induction and disease suppression.
激发子引发的防御反应会增强植物对后续病原体挑战的响应能力。我们之前表明，将脂多糖（LPS）应用于马铃薯细胞悬浮液会导致质外体酸化，但不会刺激脂氧合酶（LOX）活性。在此，我们测试了各种激发子引发和诱导马铃薯细胞悬浮液中防御反应的能力。在第二次用LPS激发前18小时向细胞培养物中添加20微克/毫升的LPS、海带多糖、harpin N或致病疫霉的浓缩培养滤液（CCF），与单次应用LPS相比，质外体酸化的强度没有改变。相反，高浓度（200或400微克/毫升）的LPS、海带多糖和harpin N在经1微克/毫升CCF预处理的细胞中激活了LOX，但在经LPS、海带多糖或harpin N预处理的细胞中未激活。当第二次激发在CCF应用后18至24小时进行时，马铃薯品种宾杰的预处理细胞中LOX反应最大。这些结果表明，CCF可引发马铃薯细胞中LOX的激活，而LPS、harpin N或海带多糖则不能。最后，生物测定表明，在接种黑胫果胶杆菌之前，先用CCF处理然后用LPS处理的半块块茎的腐烂重量减少幅度略大于单独用任何一种制剂处理的半块块茎，这表明CCF对LOX诱导和病害抑制均有引发作用。
