Table 1.

Growth and developmental phenotypes of ABA metabolism and signaling mutants described in this article. Growth-related and development-related phenotypes of mutants are highlighted in green and yellow, respectively.

Species	Mutant	Gene Function	Growth		Development
			Phenotypes	Ref.	Phenotypes	Ref.
A. thaliana	aba1	ZEP	• Reduced fresh weight • Stunted root growth • Short hypocotyls after dark germination • Decreased photosystem activity • Increased number of chloroplasts • Enhanced hyponastic response • Disturbed root meristem maintenance	[8,10,59,60,61,62]	• Increased stomatal index or density	[63,64]
A. thaliana	nced3 nced5	NCED	• Reduced rosette diameter	[65]	• Increased stomatal density • Failed to decrease stomatal density in elevated CO2	[66]
A. thaliana	aba2	xanthin dehydrogenase	• Stunted growth • Glucose insensitivity • Enhanced hyponastic response • Enhanced ethylene evolution rate • Enhanced leaf emergence on plates •Disturbed root meristem maintenance	[59,61,67,68,69,70]	• Increased stomatal index and density • Increased permeability of cuticle and ROS production • Thinner cell walls • Decreased lignin and crystalline cellulose content • Decreased suberin formation • Discontinued metaxylem strands	[71,72,73,74,75,76]
A. thaliana	aba3	Moco sulfurylase	• Reduced fresh weight • Enhanced hyponastic response • Disturbed root meristem maintenance	[59,61,77]	• Increased stomatal index or density • Failed to decrease stomatal density in elevated CO2 • Discontinued metaxylem strands • Increased permeability of cuticle and ROS production	[66,71,73,78]
A. thaliana	aao3	Abscise aldehyde oxidase	• Stunted growth	[79]
A. thaliana	pyr1 pyl1 pyl2 pyl4; pyl112458; pyl duodecuple	PYR/PYL/RCAR	• Reduced plant height • Reduced rosette diameter • Reduced fresh weight • Stunted root growth	[35,37]	• Fail to decrease stomatal density in elevated CO2 • Increased cuticle permeability • Fail to induce ectopic protoxylem in presence of ABA	[66,73,74,78]
A. thaliana	hab1 abi1-2 abi2-2; hab1 abi1-2 pp2ca (triple pp2c)	PP2C	• Reduced fresh weight • Reduced leaf surface area • Stunted root growth	[80]
A. thaliana	snrk2.2/2.3/2.6 (snrk2 triple)	SnRK2	• Reduced fresh weight • Reduced stem height • Reduced leaf surface area • Stunted root growth • Enhanced leaf emergence on plates	[32,33,67]	• Increased cuticle permeability • Thinner cell walls • Decreased lignin and crystalline cellulose content	[78,81]
A. thaliana	abi1-1	PP2C	• Enhanced hyponastic response •Disturbed root meristem maintenance	[59,61]	• Increased stomatal index • Increased cuticle permeability • Fail to induce ectopic protoxylem in presence of ABA	[72,73,74,78]
A. thaliana	abi2-1	PP2C	•Disturbed root meristem maintenance	[61]	• Increased stomatal index	[72]
A. thaliana	abi3	ABI3	• Enhanced hyponastic response •Disturbed root meristem maintenance	[59,61]	• Decreased suberin formation	[76]
A. thaliana	abi4	ABI4	• Glucose insensitivity • Enhanced lateral root formation and growth	[70,82]	• Decreased suberin formation	[76]
A. thaliana	abi5	ABI5	•Disturbed root meristem maintenance	[61]	• Decreased suberin formation	[76]
A. thaliana	cyp707a1 cyp707a3	CYP707A			• Decreased stomatal index and density	[72]
A. thaliana	atbg1 atbg2	AtBG			• Increased stomatal density	[83]
S. lycopersicum	hp3	ZEP	• Increased number of chloroplasts	[10]
S. lycopersicum	notabilis	NCED	• Reduced leaf surface area • Reduced dry leaf weight • Short hypocotyls after dark germination	[84,85,86,87,88]	• Increased stomatal index and density • Altered composition of cutin and cutilcilar waxes • Decreased level of cutin	[89,90,91]
S. lycopersicum	flacca	Moco sulfurylase	• Reduced leaf surface area • Reduced dry leaf weight • Reduced fruit size • Reduced assimilation rate • Increased number of chloroplasts • Enhanced ethylene evolution rate	[10,84,85,86,88,92,93]	• Increased stomatal index and density • Altered composition of cutin and cutilcilar waxes • Decreased level of cutin	[89,90,91]
S. lycopersicum	sitiens	abscisic aldehyde oxidase	• Stunted growth • Stunted hypocotyls after dark germination • Enhanced lateral root formation • Enhanced assimilation rate • Increased number of chloroplasts	[10,84,87,88,92,93,94,95]	• Inceased stomatal index and density • Altered composition of cutin and cutilcilar waxes • Decreased level of cutin	[88,96,97]
P. sativum	wilty	xanthin dehydrogenase	• Enhanced lateral root formation	[94]
Z. mays	vp5	PDS	• Stunted root growth • Enhanced ethylene evolution rate	[98]
O. sativa	oszep	ZEP	• Enhanced shoot growth after submergence	[99]
O. sativa	osaba2	xanthin dehydrogenase	• Enhanced stem height • Overaccumulation of ROS	[13]
O. sativa	ospyl1/4/6	PYR/PYL/RCAR	• Enhanced panicle length • Enhanced fresh weight	[36]
H. vulgare	Az34	Moco biosynthesis	• Decreased net assimilation rates	[22,93]