scholarly journals Drought Resistance of 10 Ground Cover Seedling Species during Roof Greening

2019 ◽  
Author(s):  
Pengqian Zhang ◽  
Jiade Bai ◽  
Yanju Liu ◽  
Yuping Meng ◽  
Zheng Yang ◽  
...  

Abstract10 species’ drought resistance cases have been studied, including Paeonia lactiflora, Hemerocallis dumortieri, Physostegia virginiana, Iris lacteal, Hylotelephium erythrostictum, Sedum lineare, Iris germanica, Cosmos bipinnata, Hosta plantaginea and Dianthus barbatus. By researching these drought resistance cases, a suggestion can be given for roof greening. This research sets 3 drought stress scenarios by controlling the soil relative water content (RWC), including moderately drought stress (40%±2% < RWC < 45%±2%), strong drought stress (RWC < 30%±2%) and control group (RWC > 75%±2%). After the seedlings survived the drought stress, the damaging rate of permeability (DRP), total chlorophylls concentrations (Chl), superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (AsAPOD) of seedlings will be measured. Finally, a subordinate function method was applied to assess these species’ drought resistance. Cosmos bipinnata and Physostegia virginiana was dead after having suffered with moderately drought stress and strong drought stress, respectively. Although other species survived, the individual variation was huge especially for physiological and biochemical index. Hemerocallis dumortieri, Iris lactea and Hosta plantaginea’s DRP had little change when they lived in the normal water condition and suffered with drought stress. Most of the species (except Paeonia lactiflora and Sedum lineare) showed a lower SOD activity during moderately drought stress compared with the sufficient soil water condition and strong drought stress condition. The changes of plants’ POD activity and AsAPOD activity are very similar: when drought stress enhanced, the activity of protect enzyme reduced. According to the subordinate function method, the order of plants’ resistance to the drought is as follow: Hosta plantaginea > Sedum lineare > Iris germanica > Hemerocallis dumortieri > Iris lactea >Hylotelephium erythrostictum > Dianthus barbatus > Paeonia lactiflora > Physostegia virginiana > Cosmos bipinnata.

2021 ◽  
Author(s):  
Yang Cao ◽  
fei song ◽  
Xingtang Zhao ◽  
Liming He ◽  
Yaguang Zhan

Abstract Background: In this study, sodium nitrate (SNP, a donor of nitric oxide) and methyl jasmonate (MJ) were used as exogenous hormones. The experiment was conducted with the offspring (interspecific hybrid) D110 of ash and ash, and their respective parents (non-interspecific hybrid) D113 and 4-3 as experimental materials. The experiment set up three experimental groups of drought stress, exogenous hormone SNP and MJ, and a control group under normal growth (non-drought stress), to study the physiological indicators and gene expression of manchurian ash. Result: The results showed that under drought stress and exogenous application of hormone SNP or MJ, there were significant differences between hybrids and parents in plant growth, photosynthesis, defense enzyme activity, hormone content and gene expression.Conclusions: This experiment provides a new theoretical support for the existing hormone breeding methods of manchurian ash, which can improve the drought resistance of manchurian ash and increase its survival rate in the wild. Increasing the growth rate and breeding efficiency of manchurian ash brings new ideas.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jingwei Zhang ◽  
Dazhuang Huang ◽  
Xiaojie Zhao ◽  
Man Zhang

AbstractIris germanica, a species with very high ornamental value, exhibits the strongest drought resistance among the species in the genus Iris, but the molecular mechanism underlying its drought resistance has not been evaluated. To investigate the gene expression profile changes exhibited by high-drought-resistant I. germanica under drought stress, 10 cultivars with excellent characteristics were included in pot experiments under drought stress conditions, and the changes in the chlorophyll (Chl) content, plasma membrane relative permeability (RP), and superoxide dismutase (SOD), malondialdehyde (MDA), free proline (Pro), and soluble protein (SP) levels in leaves were compared among these cultivars. Based on their drought-resistance performance, the 10 cultivars were ordered as follows: ‘Little Dream’ > ‘Music Box’ > ‘X’Brassie’ > ‘Blood Stone’ > ‘Cherry Garden’ > ‘Memory of Harvest’ > ‘Immortality’ > ‘White and Gold’ > ‘Tantara’ > ‘Clarence’. Using the high-drought-resistant cultivar ‘Little Dream’ as the experimental material, cDNA libraries from leaves and rhizomes treated for 0, 6, 12, 24, and 48 h with 20% polyethylene glycol (PEG)-6000 to simulate a drought environment were sequenced using the Illumina sequencing platform. We obtained 1, 976, 033 transcripts and 743, 982 unigenes (mean length of 716 bp) through a hierarchical clustering analysis of the resulting transcriptome data. The unigenes were compared against the Nr, Nt, Pfam, KOG/COG, Swiss-Prot, KEGG, and gene ontology (GO) databases for functional annotation, and the gene expression levels in leaves and rhizomes were compared between the 20% PEG-6000 stress treated (6, 12, 24, and 48 h) and control (0 h) groups using DESeq2. 7849 and 24,127 differentially expressed genes (DEGs) were obtained from leaves and rhizomes, respectively. GO and KEGG enrichment analyses of the DEGs revealed significantly enriched KEGG pathways, including ribosome, photosynthesis, hormone signal transduction, starch and sucrose metabolism, synthesis of secondary metabolites, and related genes, such as heat shock proteins (HSPs), transcription factors (TFs), and active oxygen scavengers. In conclusion, we conducted the first transcriptome sequencing analysis of the I. germanica cultivar ‘Little Dream’ under drought stress and generated a large amount of genetic information. This study lays the foundation for further exploration of the molecular mechanisms underlying the responses of I. germanica to drought stress and provides valuable genetic resources for the breeding of drought-resistant plants.


2021 ◽  
Author(s):  
Shifa Xiong ◽  
Yangdong Wang ◽  
Yicun Chen ◽  
Ming Gao ◽  
Yunxiao Zhao ◽  
...  

Abstract Background: Quercus fabri Hance, Quercus serrata Thunb, Quercus acutissima Carruth, and Quercus variabilis BL are four Chinese oak species commonly used for forestation. In recent years, with the global warming caused by the greenhouse effect, seedlings in mountainous areas after afforestation often suffer seasonal drought stress, which seriously affects their survival and growth. In order to ensure the survival of seedlings, we need to select oak species with strong drought resistance. Therefore, we first need to understand the differences in drought resistance of the four oak tree species at the seedling stage, and comprehensively evaluate their drought resistance capabilities by studying the changes in the physiological and biochemical characteristics of the seedlings under continuous drought and rehydration conditions.Methods: The four oak seedlings were divided into drought-rewatering treatment group and normal watering control group. For the seedlings of the drought-rewatering treatment group, drought stress lasting 31 days was used, and then re-watering and recovering for 5 days. The water parameters, osmotic adjustment substance content, antioxidant enzyme activity and photosynthesis parameters of the seedlings in the two groups were measured every 5 days. Principal component analysis, correlation analysis and membership function were used to analyze the physiological and biochemical characteristics of the seedlings of the four oak in two groups.Results and conclusions: Compared with the control group, the relative water content, water potential, net photosynthetic rate, transpiration rate, and stomatal conductance levels of the four oaks all showed a downward trend under continuous drought stress, and showed an upward trend after rehydration. The soluble protein, soluble sugar, proline, peroxidase, superoxide dismutase and catalase content of the four oaks increased first and then decreased under drought stress, and then increased after rehydration. The content of glycine betaine and malondialdehyde continued to increase, and gradually decreased after rehydration. The weight of each index was calculated by PCA, and then the comprehensive evaluation of each index was carried out through the membership function method. The drought resistance levels of the four oak species were as follows: Q. serrata > Q. fabri > Q. variabilis > Q. acutissima.


HortScience ◽  
2019 ◽  
Vol 54 (12) ◽  
pp. 2139-2145
Author(s):  
Fan Cao ◽  
Yunchu Wei ◽  
Xinwang Wang ◽  
Yongrong Li ◽  
Fangren Peng

To describe the influence of different pecan seedling rootstocks on drought stress resistance, 12 rootstocks of ‘87MX1-2.2’, ‘87MX5-1.7’, ‘Elliott’, ‘Frutoso’, ‘Giles’, ‘Major’, ‘Moore’, ‘Peruque’, ‘Posey’, ‘Riverside’, ‘San Felipe’, and ‘VC1-68’ were selected as rootstock treatments for grafting. In addition, the experimental materials for the grafted young ‘Pawnee’ tree treatments included the pressure-volume technique (PV technique) and cutting shoot transpiration methods to plot the PV and the cutting shoot transpiration curves, and the parameters calculated from the two curves were used to analyze the data produced by the subordinate function and cluster dendrogram methods. The results revealed that the different seedling rootstock treatments influenced the ‘Pawnee’ grafted trees to varying degrees on aspects of drought resistance, the ability to save water, the modulation of osmosis, and the sensitivity of the stomatal response. The order of drought tolerance for these different pecan seedling rootstock treatments from high to low was as follows: ‘Posey’, ‘Peruque’, ‘Riverside’, ‘87MX5-1.7’, ‘VC1-68’, ‘Elliott’, ‘87MX1-2.2’, ‘San Felipe’, ‘Moore’, ‘Major’, ‘Giles’, and ‘Frutoso’.


2021 ◽  
Vol 13 (7) ◽  
pp. 3910
Author(s):  
Michael Gräf ◽  
Markus Immitzer ◽  
Peter Hietz ◽  
Rosemarie Stangl

Urban green infrastructures offer thermal regulation to mitigate urban heat island effects. To gain a better understanding of the cooling ability of transpiring plants at the leaf level, we developed a method to measure the time series of thermal data with a miniaturized, uncalibrated thermal infrared camera. We examined the canopy temperature of four characteristic living wall plants (Heuchera x cultorum, Bergenia cordifolia, Geranium sanguineum, and Brunnera macrophylla) under increasing drought stress and compared them with a well-watered control group. The method proved suitable to evaluate differences in canopy temperature between the different treatments. Leaf temperatures of water-stressed plants were 6 to 8 °C higher than those well-watered, with differences among species. In order to cool through transpiration, vegetation in green infrastructures must be sufficiently supplied with water. Thermal cameras were found to be useful to monitor vertical greening because leaf surface temperature is closely related to drought stress. The usage of thermal cameras mounted on unmanned aerial vehicles could be a rapid and easy monitoring system to cover large façades.


2020 ◽  
Vol 71 (19) ◽  
pp. 6092-6106 ◽  
Author(s):  
Ping-Xia Zhao ◽  
Zi-Qing Miao ◽  
Jing Zhang ◽  
Si-Yan Chen ◽  
Qian-Qian Liu ◽  
...  

Abstract Drought is one of the most important environmental factors limiting plant growth and productivity. The molecular mechanisms underlying plant drought resistance are complex and not yet fully understood. Here, we show that the Arabidopsis MADS-box transcription factor AGL16 acts as a negative regulator in drought resistance by regulating stomatal density and movement. Loss-of-AGL16 mutants were more resistant to drought stress and had higher relative water content, which was attributed to lower leaf stomatal density and more sensitive stomatal closure due to higher leaf ABA levels compared with the wild type. AGL16-overexpressing lines displayed the opposite phenotypes. AGL16 is preferentially expressed in guard cells and down-regulated in response to drought stress. The expression of CYP707A3 and AAO3 in ABA metabolism and SDD1 in stomatal development was altered in agl16 and overexpression lines, making them potential targets of AGL16. Using chromatin immunoprecipitation, transient transactivation, yeast one-hybrid, and electrophoretic mobility shift assays, we demonstrated that AGL16 was able to bind the CArG motifs in the promoters of the CYP707A3, AAO3, and SDD1 and regulate their transcription, leading to altered leaf stomatal density and ABA levels. Taking our findings together, AGL16 acts as a negative regulator of drought resistance by modulating leaf stomatal density and ABA accumulation.


2020 ◽  
Author(s):  
Shipeng Yang ◽  
Lihui Wang ◽  
Qiwen Zhong ◽  
Guangnan Zhang ◽  
Haiwang Zhang ◽  
...  

Abstract Background Jerusalem artichoke (Helianthus tuberosus L.) is a highly stress-resistant crop, especially it grows normally in the desertified land of Qinghai-Tibet Plateau in the past two years, and has become a crop with agricultural, industrial and ecological functions. However, there are few studies on drought resistance of Jerusalem artichoke at present, and studies on the mechanisms of stress resistance of Jerusalem artichoke breeding and fructan are seriously lagging behind. In this study, we selected two differentially resistant cultivars for drought stress experiments with different concentration gradients, the aim was finding DEGs and metabolic pathways associated with drought stress. Results Based on an additional analysis of the metabolic pathways under drought stress using MapMan, the most different types of metabolism included secondary metabolism, light reaction metabolism and cell wall. As a whole, QY1 and QY3 both had a large number of up-regulated genes in the flavor pathway. It was suggested that flavonoids could help Jerusalem artichoke to resist drought stress and maintain normal metabolic activities. In addition, the gene analysis of the abscisic acid (ABA) key metabolic pathway showed that QY3 had more genes in NAC and WRKY than QY1, but QY1 had more genes in response to drought stress as a whole. By combining RNA-Seq and WGCNA, a weighted gene co-expression network was constructed and divided into modules. By analyzing specifically the expressed modules, four modules were found to have the highest correlation with drought. Further research on the genes revealed that all 16 genes related to histone, ABA and protein kinase had the highest significance in these pathways. Conclusions These findings represent the first RNA-Seq analysis of drought stress in Jerusalem artichoke, which is of substantial significance to explore the function of drought resistance in Jerusalem artichoke and the excavation of related genes.


Genetika ◽  
2005 ◽  
Vol 37 (2) ◽  
pp. 165-171 ◽  
Author(s):  
Vladislava Galovic ◽  
Zorana Kotaranin ◽  
Srbislav Dencic

Analyzed in this paper were the in vitro effects of drought stress in 13 genotypes of winter wheat, one genotype of spring wheat, and three Triticale genotypes of different geographic origin. Callus tissue was induced from immature zygotic embryos (10-15 days after pollination) on a modified MS nutrient medium. After two weeks, callus tissue was transplanted onto the same medium enriched with 5% high-molecular polyethylene glycol (PEG 6000), which was used as the stress agent to produce the effect of drought chemically. A control group of calluses was grown on an identical medium but without PEG. After four weeks of growing calluses on these mediums, we assessed callus mass survival ability of the genotypes before the transplantation as well as percentage reduction of callus fresh weight after the transplantation onto the nutrient medium with 5% PEG. Statistically significant differences were found among the genotypes in their response to the induced stress. The best survival ability before the transplantation was found in the genotype Mexicol20 (83%), while the lowest was recorded in Slavija (11.3%). Culture growing under stress conditions significantly reduced callus fresh weight in all of the genotypes. The lowest decrease of the callus mass relative to control was recorded in Rozofskaja (14.4%) and the highest in Miranovska (58.4%), indicating the genotypes' tolerance levels towards drought stress.


2020 ◽  
Author(s):  
Yuhang Liu ◽  
Zhongqun He ◽  
Yongdong Xie ◽  
Lihong Su ◽  
Ruijie Zhang ◽  
...  

Abstract A pot experiment was conducted to investigate the growth, physiological changes and mechanism of drought resistance of Phedimus aizoon L. under different levels of water content .CK: 75% ~ 80% of the MWHC (maximum water holding capacity), Mild drought: 55% ~ 60%, Moderate drought: 40% ~ 45%, Severe drought: 20% ~ 25%.We observed that the plants grew normally in the first two treatments, even the mild drought promoted the growth of the roots. In the last two treatments, drought stress had a significant negative effect on plant growth, at the same time, Phedimus aizoon L. also made positive physiological response to cope with the drought: The aboveground part of the plant (leaf, plant height, stem diameter) was smaller, the waxy layer of the leaves was thickened, the stomata of the leaves were closed during the day, and only a few stomata were opened at night, which proved that the dark reaction cycle metabolism mode of the plant was transformed from C3 cycle to CAM pathway. The activity of antioxidant enzymes (SOD, POD and CAT) was continuously increased to alleviate the damage caused by drought. To ensure the relative stability of osmotic potential, the contents of osmoregulation substances such as proline, soluble sugar, soluble protein and trehalose increased correspondingly. But plants have limited regulatory power, with aggravation of drought stress degree and extension of stress time, the MDA content and electrolyte leakage of leaves increased continuously. Observed under electron microscope,the morphology of chloroplast and mitochondria changed and the membrane structure was destroyed. The plant's photosynthetic and respiratory mechanisms are destroyed and the plant gradually die.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Jieqiong Wang ◽  
Chunhong Song ◽  
Dongmei Gao ◽  
Sheng Wei ◽  
Wenjun Sun ◽  
...  

This study is to investigate the effect of Paeonia lactiflora extract on PMS anxiety and on expression of estrogen receptor β (ERβ), tryptophan hydroxylase-2 (TPH2), and serotonin transporter (SERT) in the premenstrual syndrome (PMS) anxiety model rats. The vaginal smear and open field test were used to screen rats in nonreception phase of estrus cycle with similar macroscopic behaviors and regular estrus cycle. PMS anxiety model rats were prepared by electrical stimulation. RT-PCR and immunofluorescence were used to measure the expression of ERβ, TPH2, and SERT. Compared with normal rats, the total distance in the open field test of the model rats was significantly increased (P<0.05). The model rats showed nervous alertness, irritability, and sensitivity to external stimuli. After treatment with the Paeonia lactiflora extract, the total distance of rats was significantly reduced (P<0.05). In reception stage, there was no significant difference in the mRNA and protein expression of ERβ, TPH2, and SERT. In nonreception stage, the expression of ERβ and TPH2 in the model group was significantly decreased (P<0.05) as compared with the control group, but not SERT. Abnormal changes of the above indicators were reversed after the administration of the Paeonia lactiflora extract. In conclusion, Paeonia lactiflora extract can increase the expression of ERβ and TPH2 and decrease SERT in PMS model rats, which may be one of the mechanisms underlying the effect of Paeonia lactiflora extract on PMS.


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