Integrated Signaling Network Involving Calcium, Nitric Oxide, and Active Oxygen Species but Not Mitogen-Activated Protein Kinases in BcPG1-Elicited Grapevine Defenses

Abstract

We have already reported the identification of the endopolygalacturonase 1 (BcPG1) from Botrytis cinerea as a potent elicitor of defense responses in grapevine, independently of its enzymatic activity. The aim of the present study is the analysis of the signaling pathways triggered by BcPG1 in grapevine cells. Our data indicate that BcPG1 induces a Ca2+ entry from the apoplasm, which triggers a phosphorylation-dependent nitric oxide (NO) production via an enzyme probably related to a NO synthase. Then NO is involved in (i) cytosolic calcium homeostasis, by activating Ca2+ release from internal stores and regulating Ca2+ fluxes across the plasma membrane, (ii) plasma membrane potential variation, (iii) the activation of active oxygen species (AOS) production, and (iv) defense gene expression, including phenylalanine ammonia lyase and stilbene synthase, which encode enzymes responsible for phytoalexin biosynthesis. Interestingly enough, mitogen-activated protein kinase (MAPK) activation is independent of this regulation pathway that closely connects Ca2+, NO, and AOS.

Cross-talk between calcium-calmodulin and nitric oxide in abscisic acid signaling in leaves of maize plants

“…However, [9], and that Ca 2+ is required for H 2 O 2 -induced NO production in guard cells of mung bean [39]. The Ca 2+ -dependent NO production was also observed in tobacco cells challenged by the elicitor cryptogein [40] and in the endopolygalacturonase 1 (BcPG1)-elicited grapevine cells [41]. Here we provide evidence that both Ca 2+ and CaM are involved in ABA-and H 2 O 2 -induced NO production in leaves of maize plants.…”

“…NO has also been shown to induce an increase in the concentration of [Ca 2+ ] i in plant cells. NO may mobilize Ca 2+ from internal stores through the activation of ryanodine receptor (RYR)-like channels [15,17,40,41,[46][47][48] and plasma membrane Ca 2+ -permeable channels [40,41,47]. In the present study, our data showed that NO induced not only an increase in [Ca 2+ ] i in the protoplasts of maize leaves, which was sensitive to the plasma membrane Ca 2+ channel blocker LaCl 3 ( Figure 4A), but also increases in the expression of CaM1 ( Figure 5A) and the content of CaM in leaves of maize plants ( Figure 5B).…”

Regulation of stilbene biosynthesis in plants

“…A number of reports provided evidence that calcium signaling is implicated in the regulation of stilbene biosynthesis. According to Vandelle et al (2006), elicitor-induced influx of Ca 2?…”

“…release from the internal stores, regulation of Ca 2? fluxes across the plasma membrane, variations in plasma membrane potential, reactive oxygen species (ROS) production, activation of mitogen-activated protein kinases (MAPK), up-regulation of PAL and STS expression, and increased stilbene production levels (Poinssot et al 2003;Vandelle et al 2006 Belchí-Navarro et al (2013b), the MeJA-or CDs-induced resveratrol biosynthesis was partially dependent on Ca 2? release from internal stores.…”

“…Nitric oxide (NO) is known as a gaseous ROS belonging to the subgroup of reactive nitrogen species (RNS) that is synthesized in response to pathogen attack and can promote plant defense response (Domingos et al 2015). Vandelle et al (2006) revealed that a phosphorylation-dependent NO production is involved in the activation of PAL and STS transcription in grapevine cell suspension cultures in response to treatment with the endopolygalacturonase 1 (BcPG1), a potent fungal elicitor. Belchí-Navarro et al (2013b) supported the data demonstrating that the production of t-resveratrol in CDs-and CD ?…”