The coronatine-insensitive 1 Mutation Reveals the Hormonal Signaling Interaction between Abscisic Acid and Methyl Jasmonate in Arabidopsis Guard Cells. Specific Impairment of Ion Channel Activation and Second Messenger Production

Abstract

Methyl jasmonate (MeJA) elicits stomatal closing similar to abscisic acid (ABA), but whether the two compounds use similar or different signaling mechanisms in guard cells remains to be clarified. We investigated the effects of MeJA and ABA on second messenger production and ion channel activation in guard cells of wild-type Arabidopsis (Arabidopsis thaliana) and MeJAinsensitive coronatine-insensitive 1 (coi1) mutants. The coi1 mutation impaired MeJA-induced stomatal closing but not ABAinduced stomatal closing. MeJA as well as ABA induced production of reactive oxygen species (ROS) and nitric oxide (NO) in wild-type guard cells, whereas MeJA did not induce production of ROS and NO in coi1 guard cells. The experiments using an inhibitor and scavengers demonstrated that both ROS and NO are involved in MeJA-induced stomatal closing as well as ABAinduced stomatal closing. Not only ABA but also MeJA activated slow anion channels and Ca 21 permeable cation channels in the plasma membrane of wild-type guard cell protoplasts. However, in coi1 guard cell protoplasts, MeJA did not elicit either slow anion currents or Ca 21 permeable cation currents, but ABA activated both types of ion channels. Furthermore, to elucidate signaling interaction between ABA and MeJA in guard cells, we examined MeJA signaling in ABA-insensitive mutant ABA-insensitive 2 (abi2-1), whose ABA signal transduction cascade has some disruption downstream of ROS production and NO production. MeJA also did not induce stomatal closing but stimulated production of ROS and NO in abi2-1. These results suggest that MeJA triggers stomatal closing via a receptor distinct from the ABA receptor and that the coi1 mutation disrupts MeJA signaling upstream of the blanch point of ABA signaling and MeJA signaling in Arabidopsis guard cells.

The mutual responses of higher plants to environment: Physiological and microbiological aspects

“…So, different soil water supply will result in quite different physiological pathways, which directly determine the ability for plants to make photosynthetic products. Water deficits in soil environment also influence solute transport (ion and nutrient uptake of plants) to larger extent, which effects on photosynthetic reactions in plant chloroplasts in many ways [117,120,131,135,[139][140][141][142][143][144][145][146][147]. This is the reason that ion homeostasis and redox state have been brought to attention [4][5][6][7][21][22][23][24][25][26][27][28][29][111][112][113][114][115][116][117][118][119].…”

“…In the wide field of plant biology, its core is the study for life activities at molecular level, whose interactions at various soil-root biointerfaces at different scales are quite important to keep a steady state between plants and changing environment, especially adverse surroundings. In practice, the key point to agriculture is how to regulate the harmonious relationship between soil-environment and crops and make the best of physiological potential of crops [137][138][139][140][141][142][143][144][145][146][147]. So, adaptation in plants is an important topic in basic and applied biology under global climate change [11,[15][16][17][18][19][43][44][45][46][47][48][104][105][106][107]120].…”

The role of vacuolar processing enzymes in plant immunity

“…33 The coronatine-insensitive 1 mutation shows impaired methyl jasmonate-induced stomatal closing, but not ABA-induced stomatal closing. 35 VPE-dependent stomatal closure triggered by elicitors may play important roles in plant PTI. The evidence suggests that pathogens secrete or deliver a group of effectors into the plant cell to suppress PTI, which then inhibits stomatal closure.…”

“…Pretreatment with extracellular high Ca 2+ elicited S-type anion currents both in wild-type GCPs and in COI1 GCPs, suggesting that COI1 could function upstream of Ca 2+ sensor priming and [Ca 2+ ] cyt elevation for S-type anion channel activation. 35 Another virulent factor secreted by the bacterial phytopathogen Nicotiana benthamiana plants show typical cell death in elicitor-infected regions of leaves. VPE1a gene silencing completely suppresses cell death formation induced by harpin, but not by boehmerin or Nep1.…”

Plant Stress Surveillance Monitored by ABA and Disease Signaling Interactions

“…MeJA (methyl jasmonate) treatment induces stomatal closing through a CORONATINE INSENSITIVE1 (COI1)-and JASMO-NATE RESISTANT1 (JAR1)-dependent signaling pathway (Munemasa et al, 2007;Suhita et al, 2004). JA-triggered activation of Stype anion channel and I Ca -channel activities is probably under the control of the same second messengers elicited by ABA because MeJA does not induce stomatal closures in ABA insensitive2-1 (abi2-1) as well as in coi1 (Fig.…”