scholarly journals The Impacts of Drought Stress and Phytophthora cinnamomi Infection on Short-Term Water Relations in Two Year-Old Eucalyptus obliqua

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 109
Author(s):  
Mashlahatul Umami ◽  
Linda M. Parker ◽  
Stefan K. Arndt
Keyword(s):  
Drought Stress ◽  
Water Relations ◽  
Phytophthora Cinnamomi ◽  
Cumulative Effect ◽  
Biomass Accumulation ◽  
Short Term ◽  
Shoot Ratio ◽  
Plant Water Potential ◽  
Plant Photosynthesis ◽  
Effects Of Drought

The effects of drought stress, Phytophthora cinnamomi infection and their interaction on water relations and growth were examined for 28 days on two year-old potted trees of Eucalyptus obliqua (L’Hér.). There were significant effects of drought stress on plant photosynthesis, stomatal conductance, biomass accumulation, plant water potential at turgor loss point and the bulk modulus of elasticity. E. obliqua was successfully infected but the trees showed only mild symptoms. Infection with P. cinnamomi led to a significant reduction in the root biomass and root-to-shoot ratio in well-watered and droughted plants but did not impact water relations. There was no observable cumulative effect of drought and P. cinnamomi infection. There are multiple potential reasons why P. cinnamomi infection did not lead to drought-like symptoms in E. obliqua, including short experimental duration, delayed infection symptoms, potential resistance of E. obliqua and a possible lower aggressiveness of the P. cinnamomi strain. Hence, our results indicate that P. cinnamomi infection will not always lead to immediate short-term symptoms, and that plants that are mildly symptomatic respond very similar to drought stress compared to non-infected trees.

A dynamic simulation of loblolly pine (Pinustaeda L.) seedling establishment based upon carbon and water balances

1988 ◽  
Vol 18 (7) ◽  
pp. 833-850 ◽  
Author(s):  
John I. Blake ◽  
Gerrit Hoogenboom
Keyword(s):  
Drought Stress ◽  
Water Potential ◽  
Loblolly Pine ◽  
Carbon Allocation ◽  
Weather Data ◽  
Soluble Carbohydrate ◽  
Plant Water ◽  
Short Term ◽  
Evaporative Demand ◽  
Plant Water Potential

A generalized simulation model, ROOTSIMU, which utilizes dynamic carbon and water balance algorithms, was modified to simulate loblolly pine (Pinustaeda L.) seedling growth and water uptake for a 100-day transplant period. The modifications included an allowance for time-dependent changes in photosynthesis and carbon allocation. Heat sums were used to control the initiation of growth. Additional compartments were added to separate the physiological functions of suberized and nonsuberized roots and secondary woody tissues. Values used to initialize the model were largely derived from the published literature. The predicted results of a simulation run using 1985 and 1986 weather data are reported. Changes in simulated plant water potential were closely related to periods of rainfall or high evaporative demand. Midday values were occasionally less than −7 MPa when evaporative demand was high. Simulated responses to the 1986 drought indicated that initial soil water potentials at planting affected survival at values of less than −0.064 MPa in a sandy soil. Simulated growth was very sensitive to the photosynthetic rate, less sensitive to initial soluble carbohydrate concentration, and insensitive to instantaneous carbon allocation in relation to drought stress. The predicted increase in total root length for 1985 corresponded to the responses reported in several controlled environmental studies, but these were generally higher than those reported under field conditions. The results suggest that the carbon balance algorithm represents potential root growth within the constraints imposed by the model assumptions. The extreme diurnal fluctuations in plant water potential indicate that one or more important components of the plant system used to regulate short-term drought stress are not represented. Both stem tissue capacitance and the hydraulic conductance of mycorrhizal mycelia at low soil moisture contents may be important in controlling short-term water deficits. Further advances in the application of similar models depend upon an evaluation of these variables and a better theoretical and experimental determination of the effects of the geometry of the transplanted root system.

scholarly journals Comparative transcriptome study of switchgrass (Panicum virgatum L.) homologous autopolyploid and its parental amphidiploid responding to consistent drought stress

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Peilin Chen ◽  
Jing Chen ◽  
Min Sun ◽  
Haidong Yan ◽  
Guangyan Feng ◽  
...  
Keyword(s):  
Drought Stress ◽  
Panicum Virgatum ◽  
Differentially Expressed ◽  
Drought Response ◽  
Sequencing Data ◽  
Short Term ◽  
Microrna Sequencing ◽  
Drought Resistant ◽  
Effects Of Drought ◽  
Physiological Tests

Abstract Background Newly formed polyploids may experience short-term adaptative changes in their genome that may enhance the resistance of plants to stress. Considering the increasingly serious effects of drought on biofuel plants, whole genome duplication (WGD) may be an efficient way to proceed with drought resistant breeding. However, the molecular mechanism of drought response before/after WGD remains largely unclear. Result We found that autoploid switchgrass (Panicum virgatum L.) 8X Alamo had higher drought tolerance than its parent amphidiploid 4X Alamo using physiological tests. RNA and microRNA sequencing at different time points during drought were then conducted on 8X Alamo and 4X Alamo switchgrass. The specific differentially expressed transcripts (DETs) that related to drought stress (DS) in 8X Alamo were enriched in ribonucleoside and ribonucleotide binding, while the drought-related DETs in 4X Alamo were enriched in structural molecule activity. Ploidy-related DETs were primarily associated with signal transduction mechanisms. Weighted gene co-expression network analysis (WGCNA) detected three significant DS-related modules, and their DETs were primarily enriched in biosynthesis process and photosynthesis. A total of 26 differentially expressed microRNAs (DEmiRs) were detected, and among them, sbi-microRNA 399b was only expressed in 8X Alamo. The targets of microRNAs that were responded to polyploidization and drought stress all contained cytochrome P450 and superoxide dismutase genes. Conclusions This study explored the drought response of 8X and 4X Alamo switchgrass on both physiological and transcriptional levels, and provided experimental and sequencing data basis for a short-term adaptability study and drought-resistant biofuel plant breeding.

EFFECTS OF DROUGHT STRESS ON THE GROWTH, WATER RELATIONS AND VASCULAR FLOWS OF YOUNG 'SUMMERKIWI' FRUIT

2011 ◽  
pp. 355-359 ◽  
Author(s):  
B. Morandi ◽  
L. Manfrini ◽  
M. Zibordi ◽  
P. Losciale ◽  
L. Corelli Grappadelli
Keyword(s):  
Drought Stress ◽  
Water Relations ◽  
Effects Of Drought

scholarly journals Quantitative Lasting Effects of Drought Stress at a Growth Stage on Soybean Evapotranspiration and Aboveground BIOMASS

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Yi Cui ◽  
Shaowei Ning ◽  
Juliang Jin ◽  
Shangming Jiang ◽  
Yuliang Zhou ◽  
...  
Keyword(s):  
Drought Stress ◽  
Aboveground Biomass ◽  
Growth Stage ◽  
Biomass Yield ◽  
Biomass Accumulation ◽  
Agricultural Drought ◽  
Drought Risk ◽  
After Effects ◽  
Effects Of Drought ◽  
High Biomass Yield

Quantifying the lasting effects of drought stress on crop growth is a theoretical basis for revealing agricultural drought risk mechanism and formulating adaptive irrigation strategies. Based on two-season pot experiments of soybean in the Huaibei Plain, quantitative responses of plant evapotranspiration and aboveground biomass at each growth stage from a drought were carried out. The results showed that drought stress at a certain stage of soybean not only significantly reduced the current evapotranspiration and aboveground biomass accumulation during this stage, compared with full irrigation, but also generated the after-effects, which resulted in the reductions of evapotranspiration and biomass accumulation at the subsequent periods. Furthermore, the damaged transpiration and growth mechanism caused by drought gradually recovered through the rewatering later, and the compensation phenomenon even occurred. Nevertheless, the specific recovery effect was decided by both the degree and period of drought before. It is practical to implement deficit irrigation at the seedling and branching stages, but the degree should be controlled. Meanwhile, it is crucial to ensure sufficient water supply during the reproductive growth phase, especially at the flowering and pod-enlargement stage, to guarantee a normal transpiration function and a high biomass yield for soybeans in the Huaibei Plain.

scholarly journals Drought stress in plants: An overview on implications, tolerance mechanisms and agronomic mitigation strategies

2019 ◽  
Vol 6 (4) ◽  
pp. 389-402 ◽  
Author(s):  
Sadam Hussain ◽  
Saddam Hussain ◽  
Tauqeer Qadir ◽  
Abdul Khaliq ◽  
Umair Ashraf ◽  
...  
Keyword(s):  
Drought Stress ◽  
Biomass Accumulation ◽  
Co2 Assimilation ◽  
Mitigation Strategies ◽  
Limiting Factors ◽  
Factors Affecting ◽  
Cell Membrane Stability ◽  
Chlorophyll Contents ◽  
Final Yield ◽  
Effects Of Drought

Drought is considered as one of the major limiting factors affecting growth and productivity of crop plants. It severely affects the morphological and physiological activities of the plants and hampers the seed germination, root proliferation, biomass accumulation and final yield of field crops. Drought stress disrupts the biosynthesis of chlorophyll contents, carotene and decreases photosynthesis in plants. It gradually reduces CO2 assimilation rates owing to decrease in stomatal conductance. In addition, drought affects cell membrane stability and disrupts water relations of a plant by reducing water use efficiency. To cope with these situations, plants adopt different mechanisms such as drought tolerance, avoidance and escape. In this review, we discussed about the effects of drought on morphological and physiological characteristics of plants and suggested the different agronomic practices to overcome the deleterious effects of drought stress.

The Effects of Drought Stress on the Photosynthetic Parameters and Dry Leaf Yield of Stevia rebaudina Bertoni

2012 ◽  
Vol 518-523 ◽  
pp. 4786-4789 ◽  
Author(s):  
Guang Xi Ren ◽  
Yan Shi
Keyword(s):  
Drought Stress ◽  
Transpiration Rate ◽  
Photosynthetic Parameters ◽  
Short Term ◽  
Leaf Production ◽  
Stress Treatment ◽  
Leaf Yield ◽  
Maximum Decrease ◽  
Effects Of Drought ◽  
Mild Drought

The effects of drought stress on the photosynthesis and dry leaf yield in the different Stevia rebaudina Bertoni germplasms of: IS-1, QF-1, QTZ4, JD-1 and AL-4 was studied with the pot method in greenhouse. The results indicated that the net photosynthetic (Pn), transpiration rate (Tr) and dry leaf production of stevia showed different degree changes with the continuing of drought-stress time. There was no significant change in Pn, Tr and dry leaf production in short-term drought-stress treatment(Ta:5d), but as the time of drought-stress continuing, the Pn were on the declining trend: the Pn of various materials in T2 (without irrigation for 10d) showed maximum decrease, they decreased for 28.85%, 47.04%, 43.03%, 43.61% and 42.25% than that in T1 (without irrigation for 5d), respectively. The variation trend of Tr in various materials were the same to the Pn. And it indicated that there was no appreciable impact on the dry leaf yield in the mild drought (without water for 5d), but with the drought stress continuing, the dry leaf yield of per plant became less and less. The varying degrees decreases of dry leaf yield in different materials with the same drought stress showed that different materials with different tolerance to drought stress.

scholarly journals Increasing Inflorescence Dry Weight and Cannabinoid Content in Medical Cannabis Using Controlled Drought Stress

HortScience ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 964-969 ◽  
Author(s):  
Deron Caplan ◽  
Mike Dixon ◽  
Youbin Zheng
Keyword(s):  
Drought Stress ◽  
Cannabis Sativa ◽  
Dry Weight ◽  
Leaf Angle ◽  
Management Technique ◽  
Medical Cannabis ◽  
Stress Threshold ◽  
Cannabidiolic Acid ◽  
Plant Water Potential ◽  
Effects Of Drought

Controlled application of drought can increase secondary metabolite concentrations in some essential oil-producing crops. To evaluate the effects of drought on cannabis (Cannabis sativa L.) inflorescence dry weight and cannabinoid content, drought stress was applied to container-grown cannabis plants through gradual growing substrate drying under controlled environment. Fertigation was withheld during week 7 in the flowering stage until midday plant water potential (WP) was approximately −1.5 MPa (drought stress threshold). This occurred after 11 days without fertigation. A well-irrigated control was used for comparison. Leaf net photosynthetic rate (Pn), plant WP, wilting (leaf angle), and volumetric moisture content (VMC) were monitored throughout the drying period until the day after the drought group was fertigated. At the drought stress threshold, Pn was 42% lower and plant WP was 50% lower in the drought group than the control. Upon harvest, drought-stressed plants had increased concentrations of major cannabinoids tetrahydrocannabinol acid (THCA) and cannabidiolic acid (CBDA) by 12% and 13%, respectively, compared with the control. Further, yield per unit growing area of THCA was 43% higher than the control, CBDA yield was 47% higher, ∆9-tetrahydrocannabinol (THC) yield was 50% higher, and cannabidiol (CBD) yield was 67% higher. Controlled drought stress may therefore be an effective horticultural management technique to maximize both inflorescence dry weight and cannabinoid yield in cannabis, although results may differ by cannabis cultivar or chemotype.

Photosynthesis and Growth of Magnolia × soulangiana in Response to Consecutive Drought Stress

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 539b-539
Author(s):  
R.T. Fernandez ◽  
R.E. Schutzki
Keyword(s):  
Soil Moisture ◽  
Drought Stress ◽  
Moisture Content ◽  
Shoot Growth ◽  
Soil Moisture Content ◽  
Growth Characteristics ◽  
Leaf Photosynthesis ◽  
Short Term ◽  
Whole Plant ◽  
Plant Photosynthesis

Responses of Magnolia × soulangiana `Jane' to consecutive short-term drought stresses were evaluated in this study. Plants were received from a commercial nursery in 19-L containers in a 4:1 pine bark:sand media. In Oct. 1997, plants were exposed to one, two or three consecutive 3-day drought stress periods, each separated by one rewatering period. There were 48 total plants with eight replicates per treatment for each stress period. Following each stress period, a group of eight control and eight stressed plants were planted in the field and well-watered to monitor recovery from each stress duration. Whole-plant photosynthesis, leaf photosynthesis, shoot growth, and soil moisture content were measured approximately every 2 days during the stress periods. Leaf photosynthesis, shoot growth, and leaf defoliation rate were monitored for recovering plants. Few differences in growth were noticed except more rapid defoliation with onset of autumn for the three 3-day stressed plants. Whole-plant and leaf photosynthesis were reduced by day 3 of the first 3-day stress for drought-stressed plants and remained lower while plants were under stress. After release from stress, photosynthesis returned to control levels for plants receiving one and two 3-day stress treatments in ≈1 week, while it was more than 3 weeks until recovery for plants receiving three 3-day stress treatments. Plants will be evaluated in Spring 1998 for bloom and growth characteristics.

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