Nitric oxide is involved in abscisic acid-induced photosynthesis and antioxidant system of tall fescue seedlings response to low-light stress

Low light intensity is common in northern China due to fog or haze, and causes stress for crop plants. To solve the problem of low light intensity stress on the growth and development of vegetable crops in China, new cropping strategies must be developed. We previously showed that an appropriate ratio of ammonium and nitrate (NH4+:NO3−) can alleviate the effect of low light stress on plants, although it is not clear what mechanism is involved in this alleviation. We propose the hypothesis that an appropriate ammonium/nitrate ratio (10:90) can induce NO synthesis to regulate the AsA-GSH cycle in mini Chinese cabbage seedlings under low light intensity. To test the hypothesis, we conducted a series of hydroponic experiments. The results indicated that, under low light intensity conditions, appropriate NH4+:NO3− (N, NH4+:NO3− = 10:90) decreased the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2−) in leaves compared with nitrate treatment. Exogenous nitric oxide (SNP) had the same effects on MDA, H2O2, and O2−. However, with the addition of a NO scavenger (hemoglobin, Hb) and NO inhibitors (N-nitro-l-arginine methyl ester, L-NAME), NaN3 (NR inhibitor) significantly increased the contents of MDA, H2O2, and O2-. The application of N solution enhanced the AsA-GSH cycle by increasing the activities of ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and ascorbate oxidase (AAO), compared with control (NH4+:NO3− = 0:100). Meanwhile, exogenous SNP significantly increased the above indicators. All these effects of N on AsA-GSH cycle were inhibited by the addition of Hb, L-NAME and NaN3 in N solution. The results also revealed that the N and SNP treatments upregulated the relative expression level of GR, MDHAR1, APXT, DHAR2, and AAO gene in mini Chinese cabbage leaves under low light stress. These results demonstrated that the appropriate NH4+:NO3− (10:90) induced NO synthesis which regulates the AsA-GSH cycle in mini Chinese cabbage seedlings under low light stress.

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Effect of Low Light Stress on Photosynthetic Pigments and Antioxidative Enzymes in Field Grown Indian Mustard (Brassica juncea L.) Genotypes

Journal of Agricultural Science and Technology B ◽

10.17265/2161-6264/2021.02.002 ◽

2021 ◽

Vol 11 (2) ◽

Author(s):

Kirandeep Kaur ◽

Pushp Sharma

Keyword(s):

Brassica Juncea ◽

Antioxidative Enzymes ◽

Photosynthetic Pigments ◽

Light Stress ◽

Indian Mustard ◽

Low Light ◽

Low Light Stress

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Metabolomic indicators for low-light stress in seagrass

Ecological Indicators ◽

10.1016/j.ecolind.2020.106316 ◽

2020 ◽

Vol 114 ◽

pp. 106316

Author(s):

L.L. Griffiths ◽

S.D. Melvin ◽

R.M. Connolly ◽

R.M. Pearson ◽

C.J. Brown

Keyword(s):

Light Stress ◽

Low Light ◽

Low Light Stress

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Distinction and characterisation of submergence tolerant and sensitive rice cultivars, probed by the fluorescence OJIP rise kinetics

Functional Plant Biology ◽

10.1071/fp08218 ◽

2009 ◽

Vol 36 (3) ◽

pp. 222 ◽

Cited By ~ 18

Author(s):

Ramani Kumar Sarkar ◽

Debabrata Panda

Keyword(s):

Photosynthetic Rate ◽

Oryza Sativa L ◽

Indica Rice ◽

Light Stress ◽

Elongation Growth ◽

Rice Cultivars ◽

Low Light ◽

Test Parameters ◽

Fluorescence Characteristics ◽

Low Light Stress

Rice (Oryza sativa L.) plants experience multiple abiotic stresses when they are submerged. In addition to the effects of submergence on gas exchange, water also creates shading of submerged plants. It is believed that responses to submergence are actually responses to low light stress, although during complete submergence in addition to low light other environmental factors like reduce movement of gases affect the plant growth, and therefore, the consequences of submergence are not always alike to shade. We monitored the extent to which shade and submergence change the plant height, chlorophyll a fluorescence characteristics and CO2 photosynthetic rate in three Indica rice cultivars, namely Sarala, Kalaputia and Khoda, which differed in submergence tolerance. There were both similarities and dissimilarities between the consequence of shade and submergence on rice plants. Under shade conditions, elongation growth was greater in submergence tolerant cultivars than the sensitive cultivar, whereas elongation growth was greater under submergence in sensitive cultivar. The reduction in chlorophyll content, damage to PSII, and decrease in CO2 photosynthetic rate was more notable under submergence than the shade conditions. Our results show that several JIP-test parameters clearly distinguish between submergence tolerant and sensitive cultivars, and responses to submergence among different rice cultivars differ depending on their sensitivity to submergence. There were different interactions between cultivar and shade (~low light) and cultivar and submergence.

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