scholarly journals Effects of repeated drought stress on the physiological characteristics and lipid metabolism of Bombax ceiba L. during subsequent drought and heat stresses

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yanling Zheng ◽  
Zhining Xia ◽  
Jianrong Wu ◽  
Huancheng Ma

Abstract Background Trees of Bombax ceiba L. could produce a large number of viable seeds in the dry-hot valleys. However, the seedling regeneration of the species is difficult in these areas as mild drought often occur repeatedly which might be followed by heat stress. However, how the repeated drought affects the subsequent drought and heat tolerance of B. ceiba is not clear. In this study, chlorophyll fluorescence, soluble sugar content and lipid metabolism were measured for the drought-treated seedlings and heat-treated seedlings with or without drought hardening. Results Neither the first nor third dehydration treatments affected the photosynthetic activity and soluble sugar content of B. ceiba seedlings. However, they differentially affected the fluidity of the local membranes and the levels of diacylglycerol and phosphatidic acid. Heat shock severely decreased the photosynthetic efficiency but drought priming reduced the effects of heat shock. Moreover, heat shock with or without drought priming had differential effects on the metabolism of soluble sugars and some lipids. In addition, the unsaturation level of membrane glycerolipids increased following heat shock for non-drought-hardened seedlings which, however, maintained for drought-hardened seedlings. Conclusions The results suggest that two cycles of dehydration/recovery can affect the metabolism of some lipids during the third drought stress and may enhance the heat tolerance of B. ceiba by adjusting lipid composition and membrane fluidity.

2019 ◽  
Vol 61 (1) ◽  
pp. 169-177 ◽  
Author(s):  
Kunyang Zhuang ◽  
Yangyang Gao ◽  
Zhuangbin Liu ◽  
Pengfei Diao ◽  
Na Sui ◽  
...  

Abstract Heat stress poses a major threat to plant productivity and crop yields. The induction of heat shock proteins (HSPs) by heat shock factors is a principal defense response of plants exposed to heat stress. In this study, we identified and analyzed the heat stress-induced Whirly1 (SlWHY1) gene in tomato (Solanum lycopersicum). We generated various SlWHY1-overexpressing (OE) and SlWHY1-RNA interference (RNAi) lines to investigate the role of WHIRLY1 in thermotolerance. Compared with the wild type (WT), the OE lines showed less wilting, as reflected by their increased membrane stability and soluble sugar content and reduced reactive oxygen species (ROS) accumulation under heat stress. By contrast, RNAi lines with inhibited SlWHY1 expression showed the opposite phenotype and corresponding physiological indices under heat stress. The heat-induced gene SlHSP21.5A, encoding an endoplasmic reticulum-localized HSP, was upregulated in the OE lines and downregulated in the RNAi lines compared with the WT. RNAi-mediated inhibition of SlHSP21.5A expression also resulted in reduced membrane stability and soluble sugar content and increased ROS accumulation under heat stress compared with the WT. SlWHY1 binds to the elicitor response element-like element in the promoter of SlHSP21.5A to activate its transcription. These findings suggest that SlWHY1 promotes thermotolerance in tomato by regulating SlHSP21.5A expression.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2279
Author(s):  
Pin-Hua Lin ◽  
Yun-Yang Chao

The purpose of this experiment is to study the effects of treatment with 90% (28.5% volumetric water content (VWC)), 75% (24% VWC), 50% (16% VWC), and 25% (8% VWC) of water requirements on the growth of two djulis (Chenopodium formosana Koidz) varieties (red: RP and yellow: OR) and one quinoa (Chenopodium quinoa Willd) varieties (PI). The results showed that drought stress (8% VWC) significantly reduced plant growth and relative water content, and increased H2O2 and MDA content in C. formosana and C. quinoa. The most significant increase in these parameters was detected in the OR variety. The antioxidant enzymes, such as SOD, APX, and GR activities of PI variety under drought treatment (8% VWC), are significantly increased, while GR activity of C. formosana also increased significantly. Additionally, C. formosana and PI variety remained at a stable AsA/DHA ratio, but the GSH/GSSG ratio decreased during drought treatment. Moreover, drought stress increased total soluble sugars and proline content in the PI variety. However, C. formosana proline content was extremely significantly enhanced, and only the OR variety increased the total soluble sugar content at the same time during the vegetative growth period. In summary, C. formosana and C. quinoa have different drought tolerance mechanisms to adapt to being cultivated and produced under severe drought conditions.


2017 ◽  
Vol 42 (3) ◽  
pp. 475-485 ◽  
Author(s):  
JA Chowdhury ◽  
MA Karim ◽  
QA Khaliq ◽  
AU Ahmed

An experiment was conducted in a venylhouse at the environmental stress site of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during September to December 2012 to study the effect of drought stress on proline content, soluble sugar content, chlorophyll content and cell membrane stability of soybean genotypes. Four studied genotypes viz., Shohag, BARI Soybean-6 and BD2331 (relatively stress tolerant) and BGM2026 (susceptible) were tested against two water regimes such as water stress and non-stress. Results indicated that due to drought stress there was an increase in proline content and soluble sugar content and decrease in chlorophyll a content, chlorophyll b content, total chlorophyll content, chlorophyll a/b ratio and cell membrane stability. Proline and soluble sugar showed more content in tolerant genotype than in susceptible ones. Chlorophyll reduction was most significant and cell membrane stability was found minimal in susceptible genotypes. From the result, genotype BGM2026 which recorded the lowest proline, soluble sugar content and highest chlorophyll reduction and cell membrane injury was considered as drought susceptible. The variety/genotype of soybean such as BARI Soybean-6, Shohag and BD2331 were more drought stress tolerant and better mechanisms of drought tolerance.Bangladesh J. Agril. Res. 42(3): 475-485, September 2017


2021 ◽  
Author(s):  
Yun Li ◽  
Yanyan Jiang ◽  
Shiting Fan ◽  
Xiaolong Gan ◽  
Dong Cao ◽  
...  

Abstract Background Amylose biosynthesis is strictly associated with granule-bound starch synthase I (GBSSI) encoded by the Waxy gene. Waxy barley has extensive prospects for application in functional food development and the brewing industry; however, amylose-free waxy barleys are relatively scarce in nature. Results Here we created new alleles of the Waxy gene using CRISPR/Cas9 genome editing. Mutagenesis of single bases in these novel alleles caused absence of intact waxy protein in grain of the edited line. Consequently, B-type granules disappeared. The amylose and amylopectin contents of the edited line were zero and 31.73%, while those in the wild type (WT) were 33.50% and 39.00%, respectively. The absence of waxy protein led to increase in soluble sugar content to 37.30% compared with only 10.0% in the WT. Typical soluble sugars, sucrose and β-glucan, were 39.16% and 35.40% higher in the edited line than in the WT, respectively. Transcriptome analysis identified differences between the edited line and the WT that could partly explain the reduction in amylose and amylopectin contents and the increase in soluble sugar, sucrose and β-glucan contents. Conclusions The barley cultivar with novel alleles of the Waxy gene contained zero amylose, lower amylopectin, and higher soluble sugar, sucrose and β-glucan than the wild type. This new cultivar provides a good germplasm resource for improving the quality of barley.


2021 ◽  
Vol 48 (No. 4) ◽  
pp. 174-182
Author(s):  
Xiangyi Wu ◽  
Wei Han ◽  
Zaiqiang Yang ◽  
Yixuan Zhang ◽  
Yanjiao Zheng

Plenty of studies have demonstrated that DIF has an effect on the fruit growth. To study the effects of day and night temperature differences on the strawberry sugar quality, an experiment using climate chambers was conducted. Five different differences between the day and night temperatures (DIF) were set, which were 6 °C (28 °C/22 °C, day/night temperature), 8 °C (29 °C/21 °C), 10 °C (30 °C/20 °C), 12 °C (31 °C/19 °C), 14 °C (32 °C/18 °C). The results showed the following indices peaked with a DIF of 12 °C, including the photosynthesis rate, glucose content, fructose content, sucrose content, soluble sugar content and sugar metabolic enzyme activity. The respiration rate increased with the DIF during the day and decreased with the DIF at night. The root dry weight peaked at a DIF of 10 °C, the stolon dry weight peaked at a DIF of 8 °C and the leaf dry weight peaked at a DIF of 6 °C; however, the fruit dry weight reached maximum values at a DIF of 12 °C. The Grey correlation analysis showed that the most important factor in our experiment affecting the fructose content was the sucrose phosphate synthase; however, for the sucrose, glucose, and soluble sugars, the most important factor was the photosynthesis. We found that a DIF of 12 °C (31 °C/19 °C, day/night temperature) was the most suitable for strawberry growth, especially for the sugar content accumulation.


2018 ◽  
Vol 5 (03) ◽  
Author(s):  
ARADHNA KUMARI ◽  
IM KHAN ◽  
ANIL KUMAR SINGH ◽  
SANTOSH KUMAR SINGH

Poplar clone Kranti was selected to assess the morphological, physiological and biochemical responses under drought at different levels of water stress, as it is a common clone used to be grown in Uttarakhand for making paper and plywood. The cuttings of Populus deltoides L. (clone Kranti) were exposed to four different watering regimes (100, 75, 50 and 25% of the field capacity) and changes in physiological and biochemical parameters related with drought tolerance were recorded. Alterations in physiological (i.e. decrease in relative water content) and biochemical parameters (i.e. increase in proline and soluble sugar content and build-up of malondialdehyde by-products) occurred in all the three levels of water stress, although drought represented the major determinant. Drought treatments (75%, 50% and 25% FC) decreased plant height, radial stem diameter, harvest index, total biomass content and RWC in all the three watering regimes compared to control (100% FC). Biochemical parameters like proline, soluble sugar and MDA content increased with severity and duration of stress, which helped plants to survive under severe stress. It was analyzed that for better wood yield poplar seedlings should avail either optimum amount of water (amount nearly equal to field capacity of soil) or maximum withdrawal up to 75% of field capacity up to seedling establishment period (60 days). Furthermore, this study manifested that acclimation to drought stress is related with the rapidity, severity, and duration of the drought event of the poplar species.


2011 ◽  
Vol 356-360 ◽  
pp. 2763-2766 ◽  
Author(s):  
Yang Fan Gao ◽  
Ming Wang Shi ◽  
Jian Hua Wang

In this article, we studied to different concentrations of MCPA to creeping bentgrass Growth. Through the creeping bentgrass in four different periods of chlorophyll content, MDA and soluble sugar content determination. This test result showed:With the MCPA concentration increases, creeping bentgrass decline of chlorophyll content in the same period of growth, MDA and soluble sugar content increased. MCPA used after the early pair of creeping bentgrass growth is large, to put off with MCPA handle time, to affect to creeping bentgrass growth is gradually decreased.


2010 ◽  
Vol 32 (3) ◽  
pp. 152-162 ◽  
Author(s):  
Viviana Borges Corte ◽  
Eduardo Euclydes de Lima e Borges ◽  
José Francisco de Carvalho Gonçalves ◽  
Mirian Sousa Silva

The decay of seeds is irreversible and at best can only be delayed by applying techniques that reduce the velocity of the metabolic reactions involved. There is little information on the biochemistry of tropical forest tree seeds related to their storability. It was investigated the influence of the composition of lipids and soluble sugars of two storage compartments, the cotyledons and the embryonic axis, of Melanoxylon brauna Schot. (Leguminosae- Caesalpinioideae), a hardwood known as black brauna, seeds stored at 20 ºC for 0, 3, 6, 9 and 12 months (natural ageing) and for 0, 24, 48, 72 and 96 hours at 40 ºC (accelerated ageing). The levels of fatty acids and monosaccharides varied differentially in each of the embryo storage compartments. Changes in oligosaccharide levels were similar for both types of ageing, diminishing in both compartments. Ageing can be attributed to the significant decrease of oligosaccharides and the increase of glucose in both types of ageing and both embryo compartments.


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