The Molecular Basis of ABA-Mediated Plant Response to Drought - Abiotic Stress: Plant Responses and Applications in Agriculture - page 108

RCAR PYR/PYL PP2C interactors

RCAR1 PYL9 ABI1 [1],[4] , ABI2 [1] , HAB1 [1]

RCAR2 PYL7 ABI1 [4]

RCAR3 PYL8 HAB1 [3], ABI1 [4]

RCAR4 PYL10 ABI1 [4]

RCAR5 PYL11 HAB1 [3] , ABI1 [4]

RCAR6 PYL12 PP2CA/AHG3 [2]

RCAR7 PYL13

RCAR8 PYL5 HAB1 [3] , ABI1 [4]

RCAR9 PYL6 ABI1 [1],[4] , ABI2 [1], HAB1 [1]

RCAR10 PYL4 HAB1 [2] , ABI1 [4]

RCAR11 PYR1 HAB1 [2] , ABI1 [4]

RCAR12 PYL1 HAB1 [2] , ABI1 [4]

RCAR13 PYL3 HAB1 [2]

RCAR14 PYL2 HAB1 [2]

Table 1. The nomenclature of the different soluble receptors and their PP2Cs interactors

3. Abscisic acid is not the only phytohormone in stress response

The effectiveness of ABA is regulated not only by the length of a drought or the previous
stress history of a given plant, but also by other phytohormones such as jasmonates, cytoki‐
nins and ethylene. The role of jasmonic acid (JA) has been well established in regards to
plant development and defense responses [67]. Recently, it was also shown that jasmonic
acid (JA) and methyl jasmonate (MeJA) are involved in the regulation of drought response.
When JA or MeJA are applied exogenously to plants they are converted into a biologically
active form (+)-7-iso-Jasmonoyl-L-isoleucine (JA-Ile). JA-Ile is then bound by the receptor
SCF COI complex that contains the CORONATINE INSENSITIVE1 (COI1) F-box protein
[68-69]. This interaction leads to the degradation of the repressor protein - JAZ (Jasmonate
ZIM-domain) by the 26S proteasome, it allows MYC2 (MYC DOMAIN TRANSCRIPTION
FACTOR 2) activation of a distinct JA response genes [70-72]. In the absence of JA, JAZ in‐
hibits MYC2 in order to activate the transcription of JA-inducible genes. It was showed that
MYC2 is up-regulated not only by JA, but also by ABA and drought. The described interac‐
tion between the protein specific to jasmonates - JAZ and both jasmonates and also ABA and
drought-inducible MYC2 suggest the important regulatory role of JA in an ABA-dependent
response to drought. A similar mechanism has been described in rice [73]. It was shown
that, in addition to ABA, jasmonates also trigger stomatal closure in response to drought in