<i>p</i>-Coumaric acid induces jasmonic acid-mediated phenolic accumulation and resistance to black rot disease in <i>Brassica napus</i>

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>To investigate <I>p</I>-coumaric acid (<I>p</I>CA)-induced plant resistance, the regulation of jasmonic acid (JA)-mediated phenylpropanoid biosynthesis pathway was assessed in response to pre-treatment with <I>p</I>CA or an inhibitor of 4-coumarate–CoA ligase (4CL), 3,4-(methylenedioxy) cinnamic acid (MDCA), in <I>Brassica napus</I> cultivar (cv. Mosa) following <I>Xanthomonas campestris</I> pv. <I>campestris</I> (<I>Xcc</I>) inoculation. At seven days post inoculation with <I>Xcc</I>, necrotic lesions decreased in response to <I>p</I>CA pre-treatment. JA content and expression of signaling genes (<I>COI1</I> and <I>PDF1.2</I>) were enhanced in <I>p</I>CA-pre-treated plants, along with an increase in the MYB transcriptional factor, production of anthocyanin pigment 1 (<I>PAP1</I>), which regulates phenylpropanoid biosynthesis in <I>Xcc</I>-inoculated plants. Following <I>Xcc</I> inoculation, the accumulation of epigallocatechin and epigallocatechin gallate was increased in soluble forms; however, induced accumulation of <I>p</I>CA, ferulic acid, and sinapic acid was observed in both soluble and cell wall-bound forms in response to <I>p</I>CA pre-treatment, whereas this decreased in control or MDCA pre-treated plants. The expression of phenylpropanoid biosynthesis-related genes was upregulated in plants pre-treated with <I>p</I>CA, whereas it decreased or did not change in control and MDCA pre-treated plants, following <I>Xcc</I> inoculation. These results indicate that treatment with <I>p</I>CA primed the JA-signaling mediated induction of phenylpropanoid biosynthesis to provoke disease resistance in <I>B. napus</I> to <I>Xcc</I>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Pre-treatment of <I>p</I>-coumaric acid (<I>p</I>CA) enhanced jasmonic acid (JA) signaling. </LI> <LI> <I>p</I>CA primed <I>PAP1</I>-induced upregulation of phenylpropanoid biosynthesis. </LI> <LI> <I>p</I>CA-induced alleviation of black rot disease relied on JA-mediated phenolic accumulation. </LI> </UL> </P>