Table 1.

H₂ involved in plant abiotic stress tolerance.

Plant Species	Abiotic Stress and Its Effect	H2 Roles under Stress	Reference
Alfalfa	Cd stress inhibited root elongation	Improving root growth, re-establishing glutathione homeostasis	[6]
Cabbage	Cd stress reduced the activities of the antioxidant enzyme	Enhancing the activities of the antioxidant enzyme	[8]
Cole	Cd stress affected the balance of glutathione	Governing reduced glutathione homeostasis	[72]
Alfalfa	Cd stress obviously inhibited alfalfa seedling growth	Attenuating damage in alfalfa seedlings, reducing oxidative damage	[73]
Alfalfa	Al stress increased NO production, inhibited root elongation	Improving seedling growth, decreasing NO production	[75]
Maize	Al stress inhibited seed germination, broke the ion balance	Alleviating Al toxicity, decreasing lipid peroxidation	[74]
Rice	Al stress enhanced oxidative damage	Alleviating germination inhibition, re-establishing redox homeostasis	[16]
Alfalfa	Hg stress promoted ROS production	Decreasing ROS production and alleviating oxidative stress	[76]
Arabidopsis	Salt stress increased ion outflow	Maintaining ion homeostasis, controlling sodium exclusion	[21]
Rice	Salt inhibited seed germination	The alleviation of oxidative damage	[20]
Cucumber	Temperature stress affected photosynthetic parameters	Altering photosynthetic gas exchange	[78]
Rice	Temperature stress destroyed redox homeostasis	Re-establishing redox homeostasis	[22]
Radish	UV-A stress reduced anthocyanin content	Upregulating the anthocyanin biosynthesis-related genes	[79]
Alfalfa	UV-B stress destroyed the antioxidant defense system	Reducing lipid peroxidation, regulating the antioxidant defence system	[80]
Radish	Short wavelength light stress influenced anthocyanin biosynthesis	Enriching anthocyanin content	[81]
Alfalfa	Oxidative stress enhanced oxidative damage	Increasing levels of the MsHO-1 transcript, alleviating oxidative stress	[23]
Alfalfa	Drought stress destroyed the redox balance	Modulating stomatal sensitivity, reducing transpirational water loss	[82]
Alfalfa	Drought stress affected the enzyme activity	Elevating H2O2 levels, the inhibition of NADPH oxidase	[10]