scholarly journals Compensatory growth in Microcystis aeruginosa after moderate high-temperature exposure

2015 ◽  
Author(s):  
Wei Han ◽  
Yuanshu Jing ◽  
Ting Li
Keyword(s):  
High Temperature ◽  
Antioxidant Enzyme ◽  
Chlorophyll A ◽  
Temperature Stress ◽  
Enzyme Activities ◽  
Compensatory Growth ◽  
Soluble Sugar ◽  
Recovery Phase ◽  
High Temperature Stress ◽  
Antioxidant Enzyme Activities

<p align="left">This study aimed to investigate the mechanisms involved in <em>Microcystis aeruginosa</em> (<em>M. aeruginosa</em>) compensatory growth after moderate high-temperature stress. In the experiment, <em>M. aeruginosa</em> were cultured for 3, 6, and 12 d at 35°C before being transferred to normal conditions (25°C), and then cultured for 30 days for recovery. The algae that were cultured constantly at 25°C were set as control. The results showed that the growth of <em>M. aeruginosa</em> was inhibited significantly by the moderate high-temperature stress. During the recovery phase, the <em>M. aeruginosa</em> cultured at 35°C for 3, 6, and 12 days exhibited under-compensation, over-compensation, and equal-compensation, respectively. To cope with moderate high-temperature stress, <em>M. aeruginosa</em> implement various mechanisms, including increasing antioxidant enzyme activities and chlorophyll a content; adjusting compatible solutes (soluble protein and sugar). The <em>M. aeruginosa</em> cultured at 35°C for 6 days has higher antioxidant enzyme activities, relatively low malondialdehyde content, and higher soluble sugar content during the recovery phase; therefore, <em>M. aeruginosa</em> cultured at 35°C for 6 days exhibited over-compensation growth. Grey correlation analysis revealed that the increase of chlorophyll a, soluble sugar, and superoxide dismutase activity play key roles in the compensatory growth of <em>M. aeruginosa</em>.</p>

Photosynthetic Capacity, Antioxidant Activity and Molecular Responses in Parthenocissus Quinquefolia (L.) Planch Under High Temperature Stress and Subsequent Recovery

2021 ◽  
Vol 50 (2) ◽  
pp. 433-436
Author(s):  
Yuan Xue Tao ◽  
Li Fu Ping
Keyword(s):  
High Temperature ◽  
Antioxidant Enzyme ◽  
Temperature Stress ◽  
Photosynthetic Capacity ◽  
D1 Protein ◽  
Temperature Limit ◽  
High Temperature Stress ◽  
Psii Activity ◽  
Increasing Temperature ◽  
Parthenocissus Quinquefolia

Photosynthetic capacity and photosystem II (PSII) activity decreased with increasing temperature, whereas antioxidant enzyme activity showed the opposite trend. High temperature stress induced a significant increase in Φf,D, and D1 protein turnover rate. Photosynthetic capacity, PSII activity, and antioxidant enzyme levels in plants treated at 35 and 40°C were restored to control levels upon stress relief, whereas those in plants grown at 45℃ were only partially restored. Therefore, the temperature limit for heat tolerance in Parthenocissus quinquefolia is between 40 and 45℃. Further, it was observed that antioxidant enzymes were crucial for high-temperature stress resistance in P. quinquefolia, with DEGP1 protein playing a major role in the rapid turnover of D1 protein for PSII repair. Bangladesh J. Bot. 50(2): 433-436, 2021 (June)

scholarly journals Physiological and Antioxidant Parameters in Two Lycoris Species as Influenced by Water Deficit Stress

HortScience ◽  
2015 ◽  
Vol 50 (11) ◽  
pp. 1702-1708 ◽  
Author(s):  
Sheng Xu ◽  
Mingmin Jiang ◽  
Jiangyan Fu ◽  
Lijian Liang ◽  
Bing Xia ◽  
...  
Keyword(s):  
Antioxidant Enzyme ◽  
Water Deficit ◽  
Enzyme Activities ◽  
Water Status ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Net Photosynthesis ◽  
Water Deficit Stress ◽  
Antioxidant Enzyme Activities ◽  
Guaiacol Peroxidase

From a field experiment, the changes in morphophysiological characters and antioxidant enzyme activities were studied in two Lycoris species (Lycoris radiata and Lycoris aurea) subjected to 16 days of water deficit stress. With the increase of water deficit stress processing time, leaf relative water content (RWC), membrane stability index (MSI), net photosynthesis (Pn), stomatal conductance (gS), transpiration rate (E), and chlorophyll (Chl) content decreased in both studied species. The water use efficiency (WUE) showed an opposite tendency between the two species under water deficit stress, where WUE of L. aurea decreased moderately and WUE of L. aurea increased somehow. Intercellular CO2 concentration (Ci) in L. aurea and L. radiata decreased in respond to water deficit stress at early stages of stress treatment, then increased throughout the rest of the stress period, and reached levels higher than those in well-watered plants at the end of the treatment. In addition, there was a significant increment in soluble sugar content and proline accumulation under water deficit stress in both species, and L. radiata showed a much more accumulation. The activity of superoxide dismutase (SOD), guaiacol peroxidase (POD), and ascorbate peroxidase (APX) increased in both plants subjected to water deficit stress while declined as the stress time increased. In L. aurea, catalase (CAT) showed a sustained increment, but it responded later and after a transient increase declined again in L. radiata under water deficit stress. In conclusion, L. radiata was more tolerant to water deficit stress than L. aurea as evidenced by its relatively higher water status, higher levels of proline, soluble sugar and pigments, and stronger photoprotection. Moreover, relatively higher antioxidant enzyme activities and lower levels of thiobarbituric acid reactive substances (TBARS) in L. radiata were also associated with its better protection against water deficit stress-induced oxidative damage.

Effect of NH4+-N and NO3--N Ratio on the Growth and Quality of Bunching Onion under High Temperature Stress

2011 ◽  
Vol 366 ◽  
pp. 132-135
Author(s):  
Guang Wen Sun ◽  
Cai Yong Jiang ◽  
Hou Cheng Liu ◽  
Shi Wei Song ◽  
Ri Yuan Chen
Keyword(s):  
High Temperature ◽  
Vitamin C ◽  
Temperature Stress ◽  
Nitrate Concentration ◽  
Soluble Sugar ◽  
High Temperature Stress ◽  
Allium Fistulosum ◽  
Plant Weight ◽  
Bunching Onion

The effects of different NH4+-N to NO3--N ratio (NH4+ /NO3-) (0, 1/8, 1/4 and 1/2) on growth and quality of bunching onion (Allium fistulosum L. var. caespitosum Makino) under high temperature stress (34°C/26°C, day/night) were studied in growth chamber by hydroponics. The results showed that the growth and quality of bunching onion were affected by NH4+ /NO3-. Plant weight and height, leaf number per plant were the highest in the treatment which NH4+ /NO3- was 1/8, and those in treatment without NH4+-N were higher than in other 2 treatments. With the NH4+ /NO3- increasing, nitrate concentration in bunching onion decreased. The concentration of vitamin C was the highest in the treatment which NH4+ /NO3- was 1/8, while concentration of soluble sugar, soluble protein and allicin were the highest in the treatment which NH4+ /NO3-was 1/2. Thus the growth and quality of bunching onion were better in the NH4+ /NO3- range of 1/8 to 1/4.

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