Different drought-stress responses in photosynthesis and reactive oxygen metabolism between autotetraploid and diploid rice

Abstract

Photosynthetic light curve, chlorophyll (Chl) content, Chl fluorescence parameters, malondialdehyde (MDA) content, phosphoenolpyruvate carboxylase (PEPC) activity and reactive oxygen metabolism were studied under drought stress in two autotetraploid rice lines and corresponding diploid rice lines. Net photosynthetic rate decreased dramatically, especially under severe drought stress and under high photosynthetic active radiation in diploid rice, while it declined less under the same conditions in autotetraploid lines. Compared with the corresponding diploid lines, the Chl content, maximum photochemical efficiency of photosystem (PS) II, and actual photochemical efficiency of PSII were reduced less in autotetraploid lines. PEPC activities were higher in autotetraploid rice lines. PEPC could alleviate inhibition of photosynthesis caused by drought stress. The chromosome-doubling enhanced rice photoinhibition tolerance under drought stress. The lower MDA content and superoxide anion production rate was found in the autotetraploid rice indicating low peroxidation level of cell membranes. At the same time, the superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities were higher in autotetraploid rice lines. SOD, POD, and CAT could effectively diminish the reactive oxygen species and reduced the membrane lipid peroxidation.

Yield Response of Direct Seeded <i>Aus</i> Rice Varieties under Rainfed Condition

“…However, water deficit caused impaired mitosis, cell elongation and expansion resulted in decreased growth of the number of tillers [16] and induced lesser number of effective tillers which affects its yield [17] [18]. Results are agreed with the findings of [19] and stated that plants produced lower number of effective tillers when subjected to water stress ( Table 2).…”

“…Water stress affects both expansion as well as enlargement of growth [21] of the tillers thus producing a large number of non-effective tillers. It interrupts plant net photosynthesis [19] [22], rate of transpiration [23], stomatal conductance [24], water use efficiency [25], intercellular carbon-dioxide, photosystem-II activity [26], relative water content of the cell [25] [27] [28] and ultimately membrane stability index [29]. All of these factors reduce under water shortage in rice plant [30] [31] [32].…”

Role of Reactive Oxygen Species and Contribution of New Players in Defense Mechanism under Drought Stress in Rice

“…Therefore, increasing the efficiency of antioxidant system components can be a strategy against oxidative stress and increasing drought tolerance mechanism (Table 5). For example, activities of enzymatic antioxidants like CAT, POD and SOD increases under drought stress effectively decreasing the level of intracellular ROS in rice (Yang et al, 2014). It was observed that the activity of SOD increased in rice under drought stress, exhibiting its role in detoxifying ROS under this type of abiotic stress.…”

“…Drought stress also causes early leaf senescence that starts from the leaf tips and extended through the whole rice plant parts and eventually to all tillers (Bunnag and Pongthai, 2013). Drought influence various physiological processes and induces respective responses in rice like transpiration rate, net photosynthesis, stomatal conductance, intercellular CO2, relative water contents, water use efficiency and photosystem activity (Liu et al, 2006;Chaves et al, 2009;Zlatev, 2009;Yang et al, 2014).…”

Evaluation of drought resistance in Iris germanica L. based on subordination function and principal component analysis

“…Currently, many scholars have provided large quantities of reports on the drought resistance of plants, mainly focus on the following fields: the condition of plant growth (Khalid, 2006;Rodriguez et al, 2005;Zhang et al, 2015b), the anatomical structures of leaves (Kutlu et al, 2009;Zhang et al, 2015a), the change of protective enzyme activity (Guan et al, 2015;Weng et al, 2015;Yang et al, 2014b) and the water metabolism and osmotic adjustment of plant tissue (Fu et al, 2016;Soltys-Kalina et al, 2016;Yasmin et al, 2013). With the constant development of more advanced apparatus for research, photosynthesis and chlorophyll fluorescence have also been applied in studies on the drought resistance of plants (Elsheery and Cao, 2008;Hassan, 2006;Liu et al, 2015;Ohashi et al, 2006;Zhang et al, 2015b).…”