Table 1.

Overview of the regulatory pathways of ABA-NO interaction under abiotic stresses in plants.

Stress factor	Stress conditions	Plants	Tissues	ABA and NO roles under stress	Regulatory Pathways	Antioxidant enzymes	References
Drought	Withholding irrigation	Grapevine	Leaves	• Reduced water potential, leaf area, leaves dry mass • Increased shoot length	• Antioxidant enzymes • Flavonoids pathway • Water homeostasis • Photosynthesis	APX↑, POD↑, CAT↓	Pontin et al., 2021
	PEG	Indian mustard	Leaves/Roots	• Increased leaf RWC, chlorophyll, carotenoid, protein contents • Increased ABA, NO contents • Reduced MDA, H2O2, O2 -	• Antioxidant enzymes • AsA-GSH cycle • Proline pathway • Flavonoids pathway • Water homeostasis	In the roots: SOD↑, CAT↑, APX↓, GR↓ In the leaves: SOD↓, CAT↑, APX↑, GR↓	Sahay et al., 2019
	PEG	Medicago	Seedlings	• Promoted NO, Proline accumulations • Reduced germination rate, water content	• Proline pathway • Water homeostasis	–	Planchet et al., 2014
	PEG	Bromeliaceae	Leaves	• Promoted ABA, NO, and H2O2 accumulations	• Water homeostasis	–	Mioto and Mercier, 2013
	PEG	Wheat	Root tips	• Promoted ABA, H2O2, NO formations	• ROS	–	Tari et al., 2010
	Withholding irrigation	Tb	Seedlings	• Increased RWC, photosynthetic capacity • Reduced ion leakage, MDA, plant death rate • Promoted H2O2 and NO formation	• ROS • Antioxidant enzymes • Photosynthesis • Water homeostasis	SOD↑, CAT↑	Lu et al., 2009
	0.4 M Mannitol	Wheat	Seedlings	• Reduced water loss	• Water homeostasis	–	Xing et al., 2004
	Evaporated at room temperature	Wheat	Seedlings	• Promoted ABA formation	• ROS	–	Zhao et al., 2001
Salt	NaCl	Rice	Seedlings	• Promoted ABA, NO formation • Increased RWC, Na+/K+ ratio, osmotic potential • Reduced H2O2, O2 -	• Antioxidant enzymes • Polyamines pathway, • Water homeostasis	APX↑, GST↑	Saha et al., 2022
	NaCl	Tomato	Roots	• Reduced root length, MDA • Promoted NO formation	• Antioxidant enzymes • Water homeostasis	APX↑, CAT↑	Santos et al., 2020
	NaCl	Wheat	Leaves	• Promoted ABA and Proline formations • Increased RWC	• Proline pathway • Water homeostasis	–	Ruan et al., 2004
HM	Mo	Winter wheat	Seedlings	• Promoted ABA • Reduced MDA	• Antioxidant enzymes	APX↑, CAT↑, SOD↑, POD↑	Wu et al., 2018
	Pb	Cowpeas	Leaves	• Increased stomatal conductance, leaf area, seed yield • Promoted IAA, CTK, ABA, and GA3 formations	• Hormone crosstalk	–	Sadeghipour, 2017
	Al	Rye and wheat	Roots	• Increased root elongation • Promoted IAA, ABA, and GA formations	• Hormone crosstalk	–	He et al., 2012
High light	500 μmol m−2 s−1 PPFD	Tall fescue	Seedlings	• Reduce ion leakage, MDA, ROS • Enhanced NO synthesis	• Antioxidant enzymes	APX↑, CAT↑, SOD↑, GR↑	Xu et al., 2013
Low light	40 μmol m−2 s−1 PPFD	Tall fescue	Seedlings	• Increased plant height, leaf width, tiller number, dry weight • Enhanced photosynthetic capacity • Reduced ion leakage, MDA, ROS	• Antioxidant enzymes • Photosynthesis	APX↑, CAT↑, SOD↑, POD↑	Zhang et al., 2018b
UV-B	3.3 W m-2 irradiance	Maize	Seedlings	• Promoted NO, ABA, and H2O2 formations	• ROS • ABA	–	Tossi et al., 2009
Heat	40 °C for 6 h	Wheat	Seedlings	• Increased plant length, leaf area, plant fresh weight, plant dry weight • Enhanced photosynthetic capacity • Reduced ROS, TBARS • Promoted NO, ABA formations • Promote osmoregulator production	• Antioxidant enzymes • Proline pathway • Water homeostasis • Photosynthesis	APX↑, CAT↑, SOD↑, GR↑	Iqbal et al., 2022
	45 °C in the dark for 2 h	Reed	Seedlings	• Reduced membrane permeability, MDA • Increased relative growth gate • Promoted NO, ABA formations	• ABA	–	Song et al., 2008
Chilling	CA at 12 °C for 3 d; exposed to 4 °C for 5 d	Tomato	Seedlings	• Promoted NO, ABA, and H2O2 formations	• Photosynthesis	–	Lv et al., 2018
	Pre-cooled at 0 °C for 24h	Peach	Fruits	• Reduced chilling index • Increased firmness, soluble solids content, peel color • Reduced ROS, electrolyte leakage, MDA	• Antioxidant enzymes • AsA-GSH cycle	APX↑, PAD↑, SOD↑, GR↑	Zhang et al., 2019
	4 °C for 3 d	Walnut	Shoot leaves	• Reduced ROS, MDA	• Antioxidant enzymes • AsA-GSH cycle	APX↑, CAT↑, SOD↑, GR↑	Dong et al., 2017
	4 °C for 1 d	Tomato	Seedlings	• Promoted NO, ABA, H2O2, polyamines, formations	• Polyamines pathway	–	Diao et al., 2017
	-3 °C for 3 h	Medicago	Seedlings	• Reduced ion leakage • Increased survival rate	• Antioxidant enzymes • Photosynthesis	APX↑, CAT↑, SOD↑	Guo et al., 2014
	1 °C in the dark for 6 d	Maize	Seedlings	• Increased survival percentage • Reduced ROS, MDA	• ROS • Antioxidant enzymes	CAT↑, SOD↑	Li and Zhang, 2012
Freezing	−15 °C for 1 d	Cl	Leaves	• Reduced stomatal aperture • Promoted NO, ABA, flavonoids, formations	• Antioxidant enzymes • Flavonoids pathway	CAT↑, SOD↑	Peng et al., 2022
Alkali	NaHCO3: Na2CO3 = 9:1; 0-150 mM for 12 d	NT	Seedlings	• Increased fresh weight, plant height, RWC, degree of succulency, Na+/K+ ratios • Reduced electrical leakage, ROS, MDA, stomatal aperture • Accumulation of osmoregulators	• Antioxidant enzymes • AsA-GSH cycle • Water homeostasis • Photosynthesis • Stomatal movement	APX↑, CAT↑, SOD↑, GR↑, GST↑	Zhang et al., 2023

ABA, abscisic acid; NO, nitric oxide; AsA-GSH cycle, ascorbate-glutathione cycle; PEG, polyethylene glycol; RWC, relative water content; ROS, reactive oxygen species; MDA, malondialdehyde; H₂O₂, hydrogen peroxide; O₂ ^-, superoxide radicals; Tb, Triploid bermudagrass; Mo, molybdenum; Pb, lead; Al, aluminum; HM, Heavy metal; UV-B, Ultraviolet-B; PPFD, photosynthetic photon flux density; CA, cold acclimation; TBARS, thiobarbituric acid reactive substances; Cl, Creeping lilyturf, NT, Nitraria tangutorum; CAT, catalase; SOD, superoxide dismutase; GR, glutathione reductase; APX, ascorbate peroxidase; POD, peroxidase; GST, glutathione S-transferase; IAA, auxin; CTK, cytokinin; GA, gibberellic acid.