scholarly journals Effect of drought on physiology and yield contributing characters of sunflower

1970 ◽  
Vol 35 (1) ◽  
pp. 113-124 ◽  
Author(s):  
MI Hossain ◽  
A Khatun ◽  
MSA Talukder ◽  
MMR Dewan ◽  
MS Uddin

The present study was conducted during 1995 to April 1996 at Bangladesh Agricultural University, Mymensingh to investigate the effect of drought stress at various levels with a view to studying the physiological characters of sunflower associated with yield under drought condition. Two varieties ( Kironi and Hysan-55) and five drought cycles were i) Daily watering, ii) 1 day without water, iii) 2 days without water, iv) 3 days without water, and v) 4 days without water imposed in the study. As a whole, drought treatment reduced the yield and yield contributing characters of sunflower. In most cases, the rate of reduction was higher in plants that received 4 days drought cycle followed by 3 days. The minimum reduction was observed in plants that received 1 and 2 days drought cycle. The growth parameters (CGR, RGR, NAR, and LAI) were reduced under drought treatments. Similar trend was followed in case of CSI values and RWC of the leaves. The rate of reduction for most of characters was higher in Hysan-55 than that of Kironi. Thus, the variety Kironi was found better than Hysan-55 in respect of physiological adaptation associated with yield under drought condition. Keywords: Drought; physiology; sunflower DOI: 10.3329/bjar.v35i1.5872Bangladesh J. Agril. Res. 35(1) : 113-124, March 2010

2008 ◽  
Vol 133 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Genhua Niu ◽  
Denise S. Rodriguez ◽  
Wayne Mackay

Oleander (Nerium oleander L.), native to southern Asia and the Mediterranean region, is a fast-growing evergreen shrub planted widely in the southern United States. A greenhouse study was conducted to quantify the growth and physiological responses of two cultivars, Hardy Pink and Hardy Red, and two breeding lines, EP1 and EP2, of oleander to a 12-week cyclic drought stress. Drought stress was imposed by irrigating the plants to near container capacity and then withholding irrigation until predetermined container weights were reached. Compared with the control where plants were well-irrigated throughout the experiment, shoot dry weight (DW) was reduced by 52%, 41%, 34%, and 11% in EP1, EP2, ‘Hardy Red’, and ‘Hardy Pink’, respectively. Root-to-shoot DW ratio was higher for the drought-treated plants than the control, regardless of cultivar or breeding line (hereafter, clone). The increase in root-to-shoot DW ratio from the drought treatment was highest in EP1, followed by EP2, ‘Hardy Pink’, and ‘Hardy Red.’ New shoot growth was greatest in ‘Hardy Pink’, followed by ‘Hardy Red’, EP1, and EP2. The number of newly developed shoots during the drought treatment period was 6.8, 3.0, 0.7, and 0.0 in ‘Hardy Pink’, ‘Hardy Red’, EP1, and EP2, respectively. As substrate volumetric moisture content decreased from 30%, leaf net photosynthetic rate (Pn), evapotranspiration rate (E), and stomatal conductance (gs) decreased in all clones. A curvilinear relationship between Pn and gs was found in all clones. EP1 had a lower maximum Pn (Pm) than those of ‘Hardy Pink’ and EP2 but was not different from that of ‘Hardy Red’. Predawn leaf water potential began to decrease rapidly when substrate moisture content dropped below 15% in all clones. During the dry-down, compared with the control, increases in minimal fluorescence (F0) or decreases in maximal fluorescence (Fm) and Fv/Fm (Fv = Fm – F0) in drought-stressed plants were observed in all clones, indicating some damage in photosystem II from the drought treatment. However, compared with growth parameters, the differences in physiological responses to drought stress among the clones were much smaller. ‘Hardy Pink’ was more tolerant to drought stress than ‘Hardy Red’ and the other two clones in terms of productivity because it maintained greatest growth during the drought-stress period. However, EP2 and EP1 may be more tolerant if survival is concerned because they had a higher root-to-shoot DW ratio with minimal new growth.


2020 ◽  
Vol 25 (1) ◽  
pp. 52
Author(s):  
Muhammad Abdul Aziz ◽  
Rizkita Rachmi Esyanti ◽  
Karlia Meitha ◽  
Fenny Martha Dwivany ◽  
Hany Husnul Chotimah

Chili pepper plays a significant role in the global market. However, the production is often impeded by drought stress involving WRKY genes as the defense regulator. Chitosan is considered as a promising alternative fertilizer and defense elicitor. Hence, this study aimed to determine the role of chitosan in improving plant growth and survival of red chili pepper against drought stress. At the onset of the generative phase, chili plants were subjected to 1 mg mL‐1 chitosan, 50 percent drought, or chitosan‐drought treatment. Observations were made on several growth parameters, opened stomata, and WRKY gene expression. The results showed that chitosan‐drought treatment decreased plant growth and yielded significantly. The percentage of opened stomata was recorded at 0.56‐fold lower than control. It was followed by the decrease of the relative expression of WRKY17 and WRKY53 genes up to 0.56 and 0.72‐fold lower than control, respectively. Therefore, we suggested that the double treatment of chitosan‐drought might decrease plant growth performance but increase the defense system by suppressing the expression level of the WRKY17 gene. Interestingly, the drought treatment significantly increased WRKY17 expression level up to 7‐fold higher than control. Hence, it was suggested that WRKY17 has a specific role in response to drought stress.


2021 ◽  
Author(s):  
Baozhu Li ◽  
Ruonan Fan ◽  
Guiling Sun ◽  
Ting Sun ◽  
Yanting Fan ◽  
...  

Abstract Background and aims As drought threatens the yield and quality of maize (Zea mays L.), it is important to dissect the molecular basis of maize drought tolerance. Flavonoids, participate in the scavenging of oxygen free radicals and alleviate stress-induced oxidative damages. This study aims to dissect the function of flavonoids in the improvement of maize drought tolerance. Methods Using far-infrared imaging screening, we previously isolated a drought overly insensitivity (doi) mutant from an ethyl methanesulfonate (EMS)-mutagenized maize library and designated it as doi57. In this study, we performed a physiological characterization and transcriptome profiling of doi57 in comparison to corresponding wild-type B73 under drought stress. Results Under drought stress, doi57 seedlings displayed lower leaf-surface temperature (LST), faster water loss, and better performance in growth than B73. Transcriptome analysis reveals that key genes involved in flavonoid biosynthesis are enriched among differentially expressed genes in doi57. In line with these results, more flavonols and less hydrogen peroxide (H2O2) were accumulated in guard cells of doi57 than in those of B73 with the decrease of soil water content (SWC). Moreover, the capacity determined from doi57 seedling extracts to scavenge oxygen free radicals was more effective than that of B73 under the drought treatment. Additionally, doi57 seedlings had higher photosynthetic rates, stomatal conductance, transpiration rates, and water use efficiency than B73 exposed to drought stress, resulting in high biomass and greater root/shoot ratios in doi57 mutant plants. Conclusion Flavonoids may facilitate maize seedling drought tolerance by lowering drought-induced oxidative damage as well regulating stomatal movement.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Z. Y. Su ◽  
J. J. Powell ◽  
S. Gao ◽  
M. Zhou ◽  
C. Liu

Abstract Background Fusarium crown rot (FCR) is a chronic disease in cereal production worldwide. The impact of this disease is highly environmentally dependant and significant yield losses occur mainly in drought-affected crops. Results In the study reported here, we evaluated possible relationships between genes conferring FCR resistance and drought tolerance using two approaches. The first approach studied FCR induced differentially expressed genes (DEGs) targeting two barley and one wheat loci against a panel of genes curated from the literature based on known functions in drought tolerance. Of the 149 curated genes, 61.0% were responsive to FCR infection across the three loci. The second approach was a comparison of the global DEGs induced by FCR infection with the global transcriptomic responses under drought in wheat. This analysis found that approximately 48.0% of the DEGs detected one week following drought treatment and 74.4% of the DEGs detected three weeks following drought treatment were also differentially expressed between the susceptible and resistant isolines under FCR infection at one or more timepoints. As for the results from the first approach, the vast majority of common DEGs were downregulated under drought and expressed more highly in the resistant isoline than the sensitive isoline under FCR infection. Conclusions Results from this study suggest that the resistant isoline in wheat was experiencing less drought stress, which could contribute to the stronger defence response than the sensitive isoline. However, most of the genes induced by drought stress in barley were more highly expressed in the susceptible isolines than the resistant isolines under infection, indicating that genes conferring drought tolerance and FCR resistance may interact differently between these two crop species. Nevertheless, the strong relationship between FCR resistance and drought responsiveness provides further evidence indicating the possibility to enhance FCR resistance by manipulating genes conferring drought tolerance.


2021 ◽  
Vol 5 (4) ◽  
pp. 846-853
Author(s):  
Fikret YAŞAR ◽  
Özlem ÜZAL

The purpose of the study was to determine the relationship between the messenger molecule Nitric oxide (NO) and antioxidative enzyme (SOD: Superoxide Dismutase; CAT: Catalase; APX: Ascorbate Peroxidase) activities in some metabolic changes that occur under the effect of drought stress in plants, to determine the possible roles of Nitric Oxide and to obtain complementary information. The experiment conducted in a controlled environment, and plant were cultured in containers containing Hoagland nutrient solution. For drought stress application, 10% Polyethylene Glycol (PEG 6000) was added to the nutrient solution, which is equivalent to -0.40 MPa osmotic potential. Before the drought stress is applied, pepper seedlings of Demre cv were pre-treated with different doses of Sodium Nitroprusside (SNP) and Carboxy-PTIO (potassium salt) (cPTIO) (SNP 0.01, SNP 1, SNP 100 and SNP 0.01 + cPTIO, SNP + cPTIO, SNP 100+ cPTIO). On the 10th day of the drought application, the growth parameters of the plants; the plant fresh weights and their Antioxidative Enzyme Activities (SOD, CAT, APX) were determined. In terms of plant growth parameters, both plant growth and antioxidant anzyme activities of plants pretreated with 0.01 and 1 doses of SNP were lower than the high dose of SNP and the PEG application without pretreatment. The reason for the low enzyme activities in these applications can be attributed to factors such as the excess accumulation of organic acids such as proline in the cells of the plants and the decrease in H2O2 and O-2 levels in the presence of SNP.


Proteomes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 3 ◽  
Author(s):  
Zhujia Ye ◽  
Sasikiran Reddy Sangireddy ◽  
Chih-Li Yu ◽  
Dafeng Hui ◽  
Kevin Howe ◽  
...  

Switchgrass plants were grown in a Sandwich tube system to induce gradual drought stress by withholding watering. After 29 days, the leaf photosynthetic rate decreased significantly, compared to the control plants which were watered regularly. The drought-treated plants recovered to the same leaf water content after three days of re-watering. The root tip (1cm basal fragment, designated as RT1 hereafter) and the elongation/maturation zone (the next upper 1 cm tissue, designated as RT2 hereafter) tissues were collected at the 29th day of drought stress treatment, (named SDT for severe drought treated), after one (D1W) and three days (D3W) of re-watering. The tandem mass tags mass spectrometry-based quantitative proteomics analysis was performed to identify the proteomes, and drought-induced differentially accumulated proteins (DAPs). From RT1 tissues, 6156, 7687, and 7699 proteins were quantified, and 296, 535, and 384 DAPs were identified in the SDT, D1W, and D3W samples, respectively. From RT2 tissues, 7382, 7255, and 6883 proteins were quantified, and 393, 587, and 321 proteins DAPs were identified in the SDT, D1W, and D3W samples. Between RT1 and RT2 tissues, very few DAPs overlapped at SDT, but the number of such proteins increased during the recovery phase. A large number of hydrophilic proteins and stress-responsive proteins were induced during SDT and remained at a higher level during the recovery stages. A large number of DAPs in RT1 tissues maintained the same expression pattern throughout drought treatment and the recovery phases. The DAPs in RT1 tissues were classified in cell proliferation, mitotic cell division, and chromatin modification, and those in RT2 were placed in cell wall remodeling and cell expansion processes. This study provided information pertaining to root zone-specific proteome changes during drought and recover phases, which will allow us to select proteins (genes) as better defined targets for developing drought tolerant plants. The mass spectrometry proteomics data are available via ProteomeXchange with identifier PXD017441.


2017 ◽  
Vol 68 (11) ◽  
pp. 2991-3005 ◽  
Author(s):  
Mingzhu Yin ◽  
Yanping Wang ◽  
Lihua Zhang ◽  
Jinzhu Li ◽  
Wenli Quan ◽  
...  

Abstract Environmental stress poses a global threat to plant growth and reproduction, especially drought stress. Zinc finger proteins comprise a family of transcription factors that play essential roles in response to various abiotic stresses. Here, we found that ZAT18 (At3g53600), a nuclear C2H2 zinc finger protein, was transcriptionally induced by dehydration stress. Overexpression (OE) of ZAT18 in Arabidopsis improved drought tolerance while mutation of ZAT18 resulted in decreased plant tolerance to drought stress. ZAT18 was preferentially expressed in stems, siliques, and vegetative rosette leaves. Subcellular location results revealed that ZAT18 protein was predominantly localized in the nucleus. ZAT18 OE plants exhibited less leaf water loss, lower content of reactive oxygen species (ROS), higher leaf water content, and higher antioxidant enzyme activities after drought treatment when compared with the wild type (WT). RNA sequencing analysis showed that 423 and 561 genes were transcriptionally modulated by the ZAT18 transgene before and after drought treatment, respectively. Pathway enrichment analysis indicated that hormone metabolism, stress, and signaling were over-represented in ZAT18 OE lines. Several stress-responsive genes including COR47, ERD7, LEA6, and RAS1, and hormone signaling transduction-related genes including JAZ7 and PYL5 were identified as putative target genes of ZAT18. Taken together, ZAT18 functions as a positive regulator and plays a crucial role in the plant response to drought stress.


2020 ◽  
Vol 7 (01) ◽  
pp. 28-36
Author(s):  
Hayati Minarsih Iskandar ◽  
Sonny Suhandono ◽  
Jembar Pambudi ◽  
Tati Kristianti ◽  
Riza Arief Putranto ◽  
...  

Dehydrin (DHN) is known to play an important role in plant response and adaptation to abiotic stresses (drought, high salinity, cold, heat, etc.). Previous research reported the increased expression of DHN in sugarcane stems exposed to drought stress for 15 days which may be controlled by its corresponding stress inducible promoter. The DHN promoter was succesfully isolated from sugarcane variety PSJT 941 (Pr-1DHNSo) and was cloned to pBI121 expression vector fused to a β-glucuronidase (GUS) reporter gene.  The aim of this research was the functional testing of the Pr-1DHNSo promoter through transformation into tobacco plant treated with in vitro drought stress. Genetic transformation of Pr-1DHNSo construct was conducted by Agrobacterium tumefaciens. The transformed tobacco was then subjected to drought stress treatment using 40% PEG 6000  for five sequential incubations (0, 12, 24, 48 and 72 hours). The GUS assay reveal that the transformed tobacco treated with drought stress showed a blue color denoting GUS activity in leaf, stem and root tissues and this expression increased along with the length of the drought treatment. The analysis of gusA gene using real time-qPCR normalized to the L25 reference gene also showed that the expression increased in line with the length of time of drought stress.  The results presented in this study indicated that the Pr-1DHNSo promoter from sugarcane was expressed and induced by drought stress treatment in tobacco.


2020 ◽  
Vol 19 (3) ◽  
pp. 135-147
Author(s):  
Majid Golmohammadi ◽  
Omid Sofalian ◽  
Mehdi Taheri ◽  
Alireza Ghanbari ◽  
Valiollah Rasoli

The evergreen tree olive (Olea europaea L.) is the only species of the genus Olea that produces edible fruits with high ecological and economic value. This tree species has developed a series of physiochemical mechanisms to tolerate drought stress and grow under adverse climatic environments. One of these mechanisms is photosynthesis activities, so that as yet little information achieved about the relations between olive production and photosynthetic parameters under drought conditions. An experiment was carried out during two consecutive years (2015–2017) to study the response of 20 different olive tree cultivars (Olea europaea L.) to drought stress. Several parameters like net photosynthetic rate (PN), stomatal conductance (GS), transpiration rate (TE), photosynthetic pigments (total chlorophyll, chlorophyll a, b and carotenoid) and fruit yield were measured. The results of combined analysis of variance for fruit yield and other measured traits showed that year, drought treatment, cultivar main effects and their interactions were highly significant. The results indicated that drought stress reduced all traits, however GS (42.80%), PN (37.21%) and TE (37.17%) significantly affected by drought. Lower reduction in photosynthetic performance (PN, GS and TE) in the cultivar T7 compared to other olive cultivars allowed them to maintain better fruit yield. Principal component analysis (PCA) identified two PCs that accounted for 82.04 and 83.27% of the total variation in photosynthetic parameters under optimal and drought stress conditions, respectively. Taken together, mean comparison, relative changes due to drought and biplot analysis revealed that cultivars ‘T7’, ‘Roghani’, ‘Koroneiki’, ‘Korfolia’ and ‘Abou-satl’ displayed better response against drought stress. According to our results, one olive cultivar namely ‘T7’, could be used in olive breeding programs to improve new high yielding cultivars with drought tolerance for use in the drought-prone environments.


Author(s):  
Kartika Kartika ◽  
Benyamin Lakitan ◽  
Rofiqoh Purnama Ria

Drought stress during vegetative and/or generative stages could cause massive reduction in rice yield. This study evaluated effectiveness of hydro- and osmo-priming on improving seed germination, growth and development of upland rice under drought stress during late vegetative, booting, or heading stage. Treatments consisted of hydro-priming and osmo-priming consisted of three polyethylene glycol (PEG) concentrations i.e. 10%, 15%, and 20%. Results showed that application of osmo-priming at 10% PEG required longer time (21.93 hours) to reach 50% germination, lower germination and lower vigor index. However, after germination, seeds primed with 10% PEG exhibited better seedling growth than other seed priming treatments. Effects of seed priming on yield components were overshadowed by drought exposures. Drought imposed during vegetative stage did not significantly affect yield; however, regardless of seed priming treatments, yield reduction was inevitable in rice plants exposed to drought during booting or heading stages. Rice plant shortened time to reached physiological maturity as an adaptive mechanism if drought treatment was applied during heading stage. Keywords: Germination, Polyethylene glycol, Seedling growth, Seed priming, Yield component


Sign in / Sign up

Export Citation Format

Share Document