scholarly journals Impact of High Temperature on Antioxidant Enzymes during Reproductive Phase in Rice Cultivars

Author(s):  
Shabnam Khan ◽  
Arti Guhey ◽  
V.B. Kuruwanshi
2016 ◽  
Vol 96 (3) ◽  
pp. 474-484 ◽  
Author(s):  
Yan-Qing Wu ◽  
Da-Qiu Zhao ◽  
Chen-Xia Han ◽  
Jun Tao

To clarify the theoretical basis of the differences in high temperature stress tolerance among herbaceous peony (Paeonia lactiflora Pall.), we investigated the heat injury index of twelve P. lactiflora cultivars. Of these, heat-tolerant ‘Zifengyu’ and moderately heat-tolerant ‘Hongyanzhenghui’ were selected to study the biochemical and molecular responses to high temperature stress. ‘Zifengyu’ had reduced malondialdehyde (MDA) content, increased soluble sugar, chlorophyll (Chl) a, Chl b, Chl a + b. and carotenoid contents, as well as elevated antioxidant enzymes activities, photosynthetic rate (Pn), transpiration rate (Tr) and relatively intact cellular structures compared with ‘Hongyanzhenghui’, especially when the temperature was the highest. Additionally, we isolated partial cDNAs of two heat shock protein genes (HSP60 and HSP90) from P. lactiflora, which were 880-bp and 1077-bp nucleotides in length, respectively. The expression levels of PlHSP60, PlHSP70 and PlHSP90 were lower in ‘Zifengyu’ than in ‘Hongyanzhenghui’ for the first three of four developmental stages examined. These results indicated that heat-tolerant P. lactiflora cultivar could effectively scavenge reactive oxygen species (ROS), protect cellular structures, reduce thermal damage and delay the death of plants by enhancing antioxidant enzymes activities and HSP expression under high temperature stress. These findings provide a theoretical basis for breeding heat-tolerant P. lactiflora cultivars.


Antioxidants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 510
Author(s):  
Syed Hassan Raza Zaidi ◽  
Shamsu Ado Zakari ◽  
Qian Zhao ◽  
Ali Raza Khan ◽  
Jawad Munawar Shah ◽  
...  

Effect of high temperature (HT) on anthocyanin (ANS) accumulation and its relationship with reactive oxygen species (ROS) generation in color rice kernel was investigated by using a black kernel mutant (9311bk) and its wildtype (WT). 9311bk showed strikingly higher ANS content in the kernel than WT. Just like the starch accumulation in rice kernels, ANS accumulation in the 9311bk kernel increased progressively along with kernel development, with the highest level of ANS at kernel maturity. HT exposure evidently decreased ANS accumulation in 9311bk kernel, but it increased ROS and MDA concentrations. The extent of HT-induced decline in kernel starch accumulation was genotype-dependent, which was much larger for WT than 9311bk. Under HT exposure, 9311bk had a relatively lower increase in ROS and MDA contents than its WT. This occurrence was just opposite to the genotype-dependent alteration in the activities of antioxidant enzymes (SOD, CAT and APX) in response to HT exposure, suggesting more efficiently ROS detoxification and relatively stronger heat tolerance for 9311bk than its WT. Hence, the extent of HT-induced declines in grain weight and kernel starch content was much smaller for 9311bk relative to its WT. HT exposure suppressed the transcripts of OsCHS, OsF3’H, OsDFR and OsANS and impaired the ANS biosynthesis in rice kernel, which was strongly responsible for HT-induced decline in the accumulation of ANS, C3G, and P3G in 9311bk kernels. These results could provide valuable information to cope with global warming and achieving high quality for color rice production.


2017 ◽  
Vol 13 (10) ◽  
Author(s):  
Pan Wang ◽  
Dong Li ◽  
Li-jun Wang ◽  
Benu Adhikari

AbstractThis work aimed at determining whether high temperature intermittent drying followed by tempering at ambient temperature could preserve the seed viability and vigor.JaponicaandIndicarice seeds with 21.2 % and 22.6 % wet moisture contents (w.b.) were dried at 50 ºC and 60ºC for either 5, 10, 15 or 20 minutes, followed by tempering at 25ºC for 45 minutes. Each drying cycle was repeated until the rice seeds were dried to 12.0 % (w.b.). The drying rate was improved and the total in-dryer time was reduced in the intermittent drying when compared to continuous drying, due to the tempering process. The seed vigor was significantly reduced by intermittent drying at 60 °C with all exposure times, although the seed still kept the ability to germinate for both rice cultivars. The intermittent drying at 50 ºC for 5 minutes per drying cycle preserved the seed vigor ofJaponicarice well, while inIndicarice, the intermittent drying at 50 ºC up to 20 minutes could still be able to maintain the seed vigor.


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