Leaf water potential of peanut subjected to drought stress is positively related to the oil content of peanut kernels. The aim of this study was to directly screen the high oil mutants of peanut and create the new peanut varieties using hydroxyproline as water potential regulator. In vitro mutagenesis was carried out with the embryonic leaflets of peanut variety Huayu 20 as explants and pingyangmycin as a mutagen added into the somatic embryo formation medium. The formed somatic embryos were successively transferred to somatic embryo germination and selection medium containing 6 mmol/L hydroxyproline (at -2.079 MPa water potential ) to induce regeneration and directionally screen high oil content mutants. After that, these plantlets were grafted and transplanted to the experimental field and 132 high oil mutants with oil content over 55% were obtained from the offspring of regenerated plants. Finally, among them, the oil contents of 27 lines were higher than 58% and of 2 lines were higher than 60%. A new peanut variety Yuhua 9 with high yield and oil content was bred from the regenerated plant progenies combining the pedigree breeding method. The yield was 14.0% higher than that of the control cultivar in the testing new peanut varieties of Liaoning province, and also it has passed the national registration of non-major crop varieties. Yuhua 9 with an oil content of 61.05%, which was 11.55 percentage points higher than that of the parent Huayu 20, was the peanut cultivar with the highest oil content in the world. The result showed that it was an effective way for directional breeding of high oil peanut varieties by means of the three-step technique including in vitro mutagenesis, directional screening by reducing water potential in medium and pedigree selection of regenerated plant progenies.
Arachis ; Droughts ; Germination ; Mutagenesis ; Plant Breeding

To further study the mechanism of sprout tumble caused by drought,drought stress was simulating with 30% PEG 6000,physiological,and then the morphological changes of Pinellia ternata cells at different treatment time were detected. The results indicated that,along with the period of drought stress continued,the contents of chlorophyll and water potential were decreased,relative electrical conductivity,contents of soluble sugar and MDA increased. Sprout tumble of P. ternata first occurred on the fourth day during drought stress,large scale of sprout tumble appeared on the eighth day with about 73% of tumble rate. The nuclei exposed to drought stress for 2 days were flattened,lobed,invalidated or irregular in shape and significant showed the apoptotic morphological characteristics. Adenylate transferase( ANT) gene expressions were inhibited by drought,with the rapid increase of Caspase-3 enzyme activity,the cell death rate increased. All this proves that the essence of sprout tumble caused by drought is programmed cell death,which may be a self dormancy protection mechanism of P. ternata against adverse environment.
Apoptosis ; Droughts ; Pinellia ; cytology ; Stress, Physiological

In this research,we explored the effect of three groups of water treatments,including severe drought(the corresponding water content of cultivated substrate 5%-10%),moderate drought(45%-50%) and control(85%-90%),and different drought stress time(15,30,45 d) on the glandular trichome density(TD),stomatal density(SD) and volatile exudates of Schizonepeta tenuifolia.The results showed that there were two kinds of glandular trichomes on the surface of S. tenuifolia leaves: peltate and capitate glandular trichomes. The density of capitate glandular trichomes(CTD) was higher than that of peltate glandular trichomes(PTD). Both CTD and PTD on the abaxial surface of leaf were higher than those on the adaxial surface. Under severe drought stress,the CTD and SD were higher than the other two treatments. Under the same stress time,the biomass and leaf surface area of S. tenuifolia decreased with the deepening of stress degree. As the stress time prolonged,the surface area of leaves and biomass gradually increased,and the TD and SD decreased. The most abundant compound in volatile exudates of S. tenuifolia was pulegone. Under drought stress,the relative content of pulegone decreased,and the relative content of other monoterpenoids such as D-limonene and menthone increased. The n-hexadeconic acid and 2-methyl-1-hexadecanol were detected only at the stress of 15 d,while menthone was detected at the stress of 30 d and45 d. Drought stress affected the leaf growth and secondary metabolism of S. tenuifolia.
Droughts ; Lamiaceae ; Plant Exudates ; Plant Leaves ; Trichomes

Six month old Cinnamomum cassia seedlings were used to simulate drought stress with polyethylene glycol(PEG 6000). The physiological indicators(osmotic substances, antioxidant enzymes, etc.) and chemical components of seedlings under different drought levels and the correlation between the two were studied. The results showed that the chlorophyll content and relative water content decreased gradually with the increase of PGE 6000(0, 5%, 10%, 15%) concentration and time(3, 5, 7 d), while the soluble protein content, soluble sugar content and catalase(CAT) activity increased, but the rising rate slowed down with the time. The activities of peroxidase(POD), superoxide dismutase(SOD), malondialdehyde(MDA) and proline content increased at first and then decreased. The content of coumarin, cinnamaldehyde, cinnamic acid and dimethoxycinnamaldehyde decreased, while the content of cinnamyl alcohol continued to increase.Under drought stress, the fluorescence signals of reactive oxygen species and no contents in roots of C. cassia seedlings were significantly stronger than those of the control.Further correlation analysis showed that coumarin content, di-methoxycinnamaldehyde content and osmoregulation substance content were significantly negatively correlated(P<0.05), cinnamic acid content was significantly negatively correlated with POD and SOD activities(P<0.01).It was found that C. cassia seedlings showed a certain degree of drought tolerance under short-term or mild drought stress, but if the drought exceeded a certain degree, the physiological metabolism of the seedlings would be unbalanced.
Catalase ; Cinnamomum aromaticum ; Droughts ; Malondialdehyde ; Seedlings ; Stress, Physiological ; Superoxide Dismutase

Lipids are important components of living organisms that participate in and regulate a variety of life activities. Lipids in plants also play important physiological functions in response to a variety of abiotic stresses (e.g. salt stress, drought stress, temperature stress). However, most research on lipids focused on animal cells and medical fields, while the functions of lipids in plants were overlooked. With the rapid development of "omics" technologies and biotechnology, the lipidomics has received much attention in recent years because it can reveal the composition and function of lipids in a deep and comprehensive way. This review summarizes the recent advances in the functions and classification of lipids, the development of lipidomics technology, and the responses of plant lipids against drought stress, salt stress and temperature stress. In addition, challenges and prospects were proposed for future lipidomics research and further exploration of the physiological functions of lipids in plant stress resistance.
Droughts ; Gene Expression Regulation, Plant ; Lipids ; Plants ; Stress, Physiological

Data trends show that climate is changing and several researches have shown the adverse effects of climate change to human health. This review presents how climate change affects human health. Climate change can influence the nature and severity of climate-related natural disasters such as flooding and drought, hence, increasing the rate of mortality and morbidity among human population. Climate change can also increase the likelihood of infection in humans by way of affecting the transmission of infectious diseases. Climate-induced food insecurity is also one of the consequences of climate change and this may eventually result in malnutrition and famine. There are both direct and indirect consequences of climate change to human health. First, the direct health impacts such as injuries and deaths associated with climate-induced natural disasters, and second, the indirect health impacts such as food insecurity, contaminated source of water, and increased incidence of diseases.

Human ; Climate ; Climate Change ; Disasters ; Droughts ; Floods ; Food Supply ; Incidence ; Morbidity ; Starvation ; Water ; Health ; Environmental Health

Current study was carried out to optimize the priming condition of Oldenlandia diffusa seeds, and improve germination rate and seed vigor of 0. diffusa seeds under drought conditions. Uniform design was used to optimize the concentration and priming time of three priming materials (PEG, KNO3, GA3). Different concentrations of polyethylene glycol (PEG) was used to simulate drought stress. The seedling was cultured in 1/4 Hoagland medium for 30 d. The results showed that seed priming treatment with 366 mg x kg(-1) GA3 for 1h resulted in significant increase in germination rate, germination index, vigor, root length, plant height and biomass of O. diffusa seeds under drought stress (15% PEG), while seed priming with 3.0% KNO3 for 1 h showed little effect on germination and growth of O. diffusa seeds under drought stress. Seed priming treatment with appropriate GA3 concentration and priming time could enhance seed germination and drought resistance of O. diffusa in seedling stage.
Droughts ; Germination ; Oldenlandia ; growth & development ; physiology ; Seedlings ; growth & development ; physiology ; Seeds ; growth & development ; physiology ; Stress, Physiological

Drought stress affects the growth and development of rice, resulting in severe loss in yield and quality. Ectopic expression of the bacterial RNA chaperone, cold shock protein (Csp), can improve rice drought tolerance. Archaeal TRAM (TRM2 and MiaB) proteins have similar structure and biochemical functions as bacterial Csp. Moreover, DNA replication, transcription and translation of archaea are more similar to those in eukaryotes. To test if archaeal RNA chaperones could confer plant drought tolerance, we selected two TRAM proteins, Mpsy_3066 and Mpsy_0643, from a cold-adaptive methanogenic archaea Methanolobus psychrophilus R15 to study. We overexpressed the TRAM proteins in rice and performed drought treatment at seedling and adult stage. The results showed that overexpression both TRAM proteins could significantly improve the tolerance of rice to drought stress. We further demonstrated in rice protoplasts that the TRAMs could abolish misfolded RNA secondary structure and improve translation efficiency, which might explain how TRAMs improve drought tolerance transgenic rice. Our work supports that ectopic expression of archaeal TRAMs effectively improve drought tolerance in rice.
Droughts ; Ectopic Gene Expression ; Gene Expression Regulation, Plant ; Oryza ; Plant Proteins ; Plants, Genetically Modified ; Stress, Physiological

We studied the seed germination of Astragalus membranaceus under PEG and Na Cl osmotic stress gradients( 0,-0. 1,-0. 3,-0. 5,-0. 7 MPa) respectively applied with light( continuous light,light 12 h/dark 12 h circulation and continuous dark) and temperature( constant 15 ℃,15 ℃ 12 h/30 ℃ 12 h circulation and constant 30 ℃) treatments. The results showed as following: ① Under the light and temperature interactive treatments,total germination percentage( TGP) was restrained by high temperature and continuous light also decreased TGP under high temperature. Mean germination time( MGT) was not changed by light mode. Root development was enhanced by dark and low temperature. Shoot development was enhanced by light and high temperature. Hypocotyl length was enhanced by dark and high temperature. ② Under the light and temperature interactive treatments combined respectively with PEG and NaCl stress conditions,although the inhibitions of seed germination and growth were gradually strengthened with the increases of osmotic stresses,slight osmotic stress can promote seed germination. Under the same osmotic potential,the effects of PEG on TGPs and MGTs were stronger than that of NaCl. As the temperature increase,the seeds may change from photo-neutrality to photo-phobia. Decreased TGP under drought and continuous light interactive treatment is an adaptation strategy to avoiding drought. Hypocotyl growth accelerated under continuous dark treatment is an ecological trait which could increase dry matter input in stem and height for more light. Seed development under high concentration of NaCl treatment is better than that of PEG treatment due to low water potential caused by Na~+,which can enter into seed coat and promote water absorption.
Astragalus propinquus ; physiology ; radiation effects ; Droughts ; Germination ; Light ; Salt Stress ; Seeds ; physiology ; radiation effects ; Temperature

The study is aimed to explore the effect of different water on the content of total saponins,astragaloside Ⅳ and gene expression in the growth of Astragalus membranceus. In this study, one-year-old A. membranaceus was used as the experimental material, by pot culture different water treatments were simulated at herbal garden in Jilin Agricultural University. The content of astragaloside Ⅳ was determined by HPLC and the total saponins by UV spectrophotometry. With 18 S RNA as a reference gene, fluorescent quantitative PCR was applied to analyze the eight key enzymes in astragalus saponin synthesis pathway AACT,HMGS,HMGR,IDI,FPS,SS,SE,CAS expression. With the decrease of soil water, the content of astragaloside Ⅳ in the root tissue of A. membranaceus showed an increasing trend, up to 1.46 mg·g~(-1). The total saponin content tended to increase, up to 6.80 mg·g~(-1). The results of relative expression of genes showed that the eight genes showed different effects at different water. With the change of soil water content, the amount of(AACT,IDI,SS) relative expression in drought stress group firstly increased and then decreased, then increased, and then decreased. The amount of(HMGS,HMGR,FPS) relative expression in drought stress group increased firstly and then decreased. The amount of(SE,CAS) relative expression in drought stress group increased firstly and then decreased, and continued to decrease after rehydration. The expression of key enzyme genes involved in the synthesis of astragaloside was influenced by each other, and the expression of key enzyme in roots showed a correlation with the content of astragaloside. Correlation analysis showed that there was a very significant positive correlation between HMGR gene and total saponins content in drought stress group and a significant negative correlation between content of CAS and total saponins. The contents of FPS,SE,CAS and astragaloside Ⅳ were very significantly and negative correlated. The relationship between other genes and quality was positive. Therefore, HMGR, FPS, SE and CAS genes have significant effects on the regulation of saponin content under water control. On the 15 th day after water regulation, the total amount of astragaloside and total saponins reached the highest value and could be harvested.
Astragalus Plant ; metabolism ; Chromatography, High Pressure Liquid ; Droughts ; Saponins ; biosynthesis ; Stress, Physiological ; Triterpenes ; Water