Effects of shoot excision on in situ soil and root respiration of wheat and soybean under drought stress

2006 ◽  
Vol 50 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Hong-Sheng Liu ◽  
Feng-Min Li
Keyword(s):  
Drought Stress ◽  
Root Respiration

scholarly journals Expression analysis of antioxidant genes in response to drought stress in the fl ag leaf of two Indonesian rice cultivars

2015 ◽  
Vol 19 (1) ◽  
pp. 43 ◽  
Author(s):  
R. Refli ◽  
Sukarti Muljopawiro ◽  
Kumala Dewi ◽  
Diah Rachmawati
Keyword(s):  
Drought Stress ◽  
Pcr Analysis ◽  
Severe Drought ◽  
Rice Cultivars ◽  
Chain Reaction ◽  
Antioxidant Genes ◽  
Oxidative Defense ◽  
Mda Content ◽  
The Difference

The objective of this study was to analysis the expression of antioxidant genes in response to droughtstress in Indonesian rice. The malondialdehyde (MDA) content and the expression of Cu-ZnSod1, cCu-ZnSod2,MnSod1, cApxa, cApxb, chl-sApx, Cat1, Cat2, Cat3, Gr1, Gr2, and Gr3 genes were assayed in the rice fl ag leaf ofCiherang and Situ Bagendit cultivars subjected to control, mild and severe drought during the grain fi llingphase. Increase in MDA content of Ciherang treated to mild and severe drought was almost two-fold andthree-fold respectively, while MDA content in Situ Bagendit subjected to mild and severe drought increasedapproximately one-fold and two-fold as compared to the control. The semi quantitative reverse transcriptionpolymerase chain reaction (sqRT-PCR) analysis showed that the expression of cCu-ZnSod1, MnSod1, Cat2, Gr3genes of Ciherang, and cCu-ZnSod2, MnSod1, cApxa, cApxb, chl-sAPX, Cat2 and Gr1 genes of Situ Bagendit increasedin fl ag leaf of plant treated to drought. Expressions of cApxb, chl-sApx, Cat3 of Ciherang and Cu-ZnSod1 and Gr2genes of Situ Bagendit were not changed signifi cantly by drought stress. Decreased expression was shownby cCu-ZnSod2, cApxa, Cat1, Gr1 and Gr2 genes of Ciherang, and Cat1, Cat3 and Gr3 genes of Situ Bagendit. Theresults indicated that the activity of oxidative defense was regulated by four genes; cCu-ZnSod1, MnSod1, Cat2,Gr3 in Ciherang, and eight genes; cCu-ZnSod1, cCu-ZnSod2, MnSod1, cApxa, cApxb, chl-sApx, Cat2 and Gr1 in SituBagendit. Therefore, differences in the number of antioxidant genes controlling oxidative defense systemmight determine the difference of the oxidative defense capacity between both cultivars in response to droughtstress during grain fi lling.

Diel patterns of fine root respiration in a dryland shrub, measured in situ over different phenological stages

2015 ◽  
Vol 21 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Zongrui Lai ◽  
Su Lu ◽  
Yuqing Zhang ◽  
Bin Wu ◽  
Shugao Qin ◽  
...  
Keyword(s):  
Root Respiration ◽  
Fine Root ◽  
Phenological Stages ◽  
Diel Patterns

Stand level estimation of root respiration for two subtropical plantations based on in situ measurement of specific root respiration

2009 ◽  
Vol 257 (10) ◽  
pp. 2088-2097 ◽  
Author(s):  
Dima Chen ◽  
Yang Zhang ◽  
Yongbiao Lin ◽  
Hua Chen ◽  
Shenglei Fu
Keyword(s):  
Root Respiration ◽  
In Situ Measurement

scholarly journals Mexican conifers differ in their capacity to face climate change

2017 ◽  
Vol 4 ◽  
pp. e003 ◽  
Author(s):  
Cuauhtémoc Sáenz-Romero ◽  
Maximilien Larter ◽  
Noelia González-Muñoz ◽  
Christian Wehenkel ◽  
Arnulfo Blanco-Garcia ◽  
...  
Keyword(s):  
Climate Change ◽  
Drought Stress ◽  
Natural Populations ◽  
Common Garden ◽  
Adaptation To Climate Change ◽  
Natural Habitats ◽  
Xylem Vulnerability ◽  
Adult Trees ◽  
Pinus Pseudostrobus

The recent massive dieback of forest trees due to drought stress makes assessment of the variability of physiological traits that might be critical for predicting forest response and adaptation to climate change even more urgent. We investigated xylem vulnerability to cavitation and xylem specific hydraulic conductivity in seven species of three principal conifer genera (Juniperus monticola, Juniperus deppeana, Juniperus flaccida, Pinus pseudostrobus, Pinus leiophylla, Pinus devoniana, and the endangered Picea chihuahuana) of the Mexican mountains in order to identify the species most vulnerable to future warmer and drier climates. Hydraulic traits were examined using the in situ flow centrifuge technique (Cavitron) on branches collected from adult trees of natural populations and seedlings growing in a common garden. We found evidence of significant differences in xylem safety between genera (P50: pressure inducing 50% loss of hydraulic conductance): the three juniper species exhibited low P50 values (ranging from -9.9 to -10.4 MPa), relative to the much more vulnerable pine and spruce species (P50 ranging between - 2.9 to - 3.3 MPa).  Our findings also revealed no variation in P50 between adult trees assessed in the field and seedlings growing in a common garden. We therefore propose that if, as projected, climate change makes their natural habitats much warmer and drier, populations of Mexican pines and the studied spruce will be likely to decline severely as a result of drought-stress induced cavitation, while the juniper species will survive.

scholarly journals Drought tolerance of three ethnomedicinal shrubs evaluated based on their seed germination rates at different drought levels induced by using polyethylene glycol (PEG6000)

2021 ◽  
Vol 48 (1) ◽  
pp. 49-54
Author(s):  
Mohammed Dadach ◽  
Zoheir Mehdadi
Keyword(s):  
Polyethylene Glycol ◽  
Water Stress ◽  
Drought Stress ◽  
Seed Germination ◽  
Distilled Water ◽  
Natural Habitats ◽  
Economic Interests ◽  
Seed Biology ◽  
Semi Arid

Abstract Sideritis incana, Stachys ocymastrum, and Thymus fontanesii are medicinal plants belonging to the Lamiaceae family and occurring in semi-arid lands in northern Algeria and in many other countries along the Mediterranean coastline. Despite the ecological and economic interests and also the questionable future these species may meet in their natural habitats, various aspects of their seed biology have not been recognised to this date. This study was intended for in situ conservation of these plants. The problem investigated was the germination response of seeds to different water potential levels attained with using different amounts of polyethylene glycol (PEG6000) (0, –0.03, –0.07, –0.2, –0.5, –1 and –1.6 MPa). In this way, the appropriate conditions and the threshold tolerance of seed germination against water stress were assessed. Seeds of the three species lacked primary/innate dormancy and they germinated abundant and fast in distilled water (S. incana – 65%; S. ocymastrum – 60% and T. fontanseii – 90%). Small seeds of T. fontanesii tolerated more water stress and germinated under up to –1 MPa (–10 bars). Large seeds of S. incana and S. ocymastrum, however, were more sensitive to the drought stress and germinated only under –0.5 MPa (–5 bars). Moreover, more studied parameters were found developing negative reponse under rising drought stress, such as postponed triggering of seed germination, decreased germination velocity and prolonged germination duration, as well as the average time of germination. Therefore, these three plants appear to postpone their establishment until arrival of conditions promising for germination, including sufficient rainfall.

In situ measurement of root respiration and soluble C concentrations in the rhizosphere

1993 ◽  
Vol 25 (9) ◽  
pp. 1189-1196 ◽  
Author(s):  
Cheng Weixin ◽  
David C. Coleman ◽  
C.Ronald Carroll ◽  
Carol A. Hoffman
Keyword(s):  
Root Respiration ◽  
In Situ Measurement ◽  
Soluble C

Photosynthesis and assimilate distribution in relation to yield of cassava grown in controlled environments

1976 ◽  
Vol 54 (12) ◽  
pp. 1322-1331 ◽  
Author(s):  
J. D. Mahon ◽  
S. B. Lowe ◽  
L. A. Hunt
Keyword(s):  
High Temperature ◽  
Root Respiration ◽  
Leaf Tissue ◽  
Dry Weight ◽  
Root Weight ◽  
Manihot Esculenta Crantz ◽  
Controlled Environments ◽  
Net Assimilation ◽  
Plant Respiration

Cassava (Manihot esculenta Crantz) plants were grown for 52 weeks in controlled-environment growth rooms with day/night (14/10 h) temperatures of 29/24 °C and 24/19 °C. Plants were sampled for growth analysis at monthly intervals for 36 weeks and at 52 weeks. At intervals the photosynthetic CO2 uptake by leaf parts and the respiration were measured in situ by using infrared CO2 analysis.The growth rate at both temperatures was directly related to the product of leaf photosynthesis and total leaf area, and the decreasing net assimilation rate of the high-temperature plants was reflected in the declining mean photosynthetic rates of the leaf tissue. The rate of photosynthetic CO2 uptake was between 9 and 18 mg dm−2 h−1, depending on leaf position.During the early stages of growth, the relationship between root weight and total weight was unaffected by temperature. As the plants increased in size, the proportion of dry matter in the roots increased in low-temperature plants but remained constant in high-temperature plants. The estimated plant respiration averaged 45% of the total assimilation. In high-temperature plants the root respiration was equivalent to 0.7% of the root dry weight per day and after 36 weeks the total root respiration exceeded the root growth.

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