Differential response of growth and photosynthesis in diverse cotton genotypes under hypoxia stress

Abstract

The objectives of the present study were to compare the dynamic of the growth and photosynthetic characteristics of cotton varieties contrasting in waterlogging (WL) tolerance when subjected to hypoxia stress. The growth of the WL-sensitive genotypes was notably inhibited by WL, mainly as a result of a significant reduction in the net photosynthesis (PN) after two days of hypoxia treatment; in the tolerant varieties, no significant changes in PN were observed until 8 d after hypoxia onset. The intercellular CO2 concentration and maximal photochemical efficiency of PSII significantly declined, and the nonphotochemical quenching increased in the sensitive varieties. Infrared thermography showed that a low stomatal conductance resulted in an increased leaf temperature under hypoxia stress. Spectral image analysis suggested that the pigment content and water content rapidly decreased in the leaves of the sensitive varieties. It is concluded that maintaining stomatal opening through the interaction of ethylene and abscisic acid may be an important strategy to improve waterlogging tolerance in cotton.Additional key words: chlorophyll fluorescence; Gossypium hirsutum; hyperspectral image; infrared thermal image. Abbreviations: Ci -intercellular CO2 concentration; E -transpiration rate; Fv/Fm -optimal/maximal quantum yield of PSII; gs -stomatal conductance; NDWI -normalized difference water index; NPQ -nonphotochemical quenching coefficient; PN -net photosynthetic rate; PSSRa -pigment ratio index a; qp -photochemical quenching coefficient. Acknowledgement: We appreciate the contribution of C. Li and Y.W. Nong on experimental execution. We thank to The National Natural Science Fund (No. 31471496) for financial support.

Selection of Tomato and Cucumber Accessions for Waterlogging Sensitivity through Morpho-Physiological Assessment at an Early Vegetative Stage

“…The decrease in Fv/Fm was noted in more sensitive tomato and cucumber plants in our experiments. In agreement with our results, a decrease in Fv/Fm after waterlogging was also observed in rice [54,57], cucumber [56,58], tomato [59,60], wild tomato (Solanum habrochaites S.Knapp & D.M.Spooner) [61], Arabidopsis (Arabidopsis thaliana L.) [62], cotton [39], and pepper (Capsicum annuum L.) plants [63]. Barik et al [57] examined the reaction of tolerant and susceptible varieties of rice to submergence and observed that the latter exhibited a greater reduction in Fv/Fm parameters in comparison to tolerant varieties.…”

“…Barik et al [57] examined the reaction of tolerant and susceptible varieties of rice to submergence and observed that the latter exhibited a greater reduction in Fv/Fm parameters in comparison to tolerant varieties. Similarly, in an experiment with cotton, the Fv/Fm parameter was stable in tolerant varieties and significantly decreased in sensitive varieties under hypoxia [39]. In the case of sorghum after waterlogging stress, the changes in Fv/Fm parameters were not significant, despite the observation of a substantial decrease in the Fv/F 0 parameter [64].…”

“…Therefore, it is reasonable to study the intensity of photosynthesis or chlorophyll a fluorescence during stresses involving the root system, such as hypoxia, salinity, or others that interfere in the functioning of the plant. For example, decreases in net photosynthesis as well as a decline in maximal photochemical efficiency of PSII after hypoxia have been observed in sensitive accessions of cotton [39], while in tolerant forms, the changes were not observed. The JIP-test, widely discussed since 1995, is a good tool for comparing stressed and control samples and allows investigation of the effects of almost any stress factor, although only if the stress affects photosynthesis [51].…”

“…Decreases in plant height were observed after waterlogging in cucumber [56] and field bean (Vicia faba L. minor) [65]. Six cotton varieties, sensitive and tolerant to hypoxia stress, were tested by Pan et al [39], and an inhibition in plant growth was observed in more sensitive varieties. However, plant height in stressed tolerant cotton was similar to untreated plants.…”

Aerenchyma formation in the root of leaf‐vegetable sweet potato: Programmed cell death initiated by ethylene‐mediated H2O2 accumulation

“…Previous studies showed that the net photosynthetic rate of waterlogging‐sensitive cotton significantly decreased at 2 days of hypoxia treatment (Pan et al 2019a, 2019b). In wheat, the plant height was reduced by 30% after hypoxia treatment for 8 days (Pan et al 2019a, 2019b).…”