scholarly journals Clonal variability for vulnerability to cavitation and other drought-related traits in Hevea brasiliensis Müll. Arg.

2015 ◽  
Vol 2 ◽  
pp. e001 ◽  
Author(s):  
Wanploy Jinagool ◽  
Ratchanee Rattanawong ◽  
Krissada Sangsing ◽  
Têtè Sévérien Barigah ◽  
Frederic Gay ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Rubber Tree ◽  
Stomatal Response ◽  
Plant Materials ◽  
Vulnerability To Cavitation ◽  
Xylem Vulnerability ◽  
Precipitation Regimes ◽  
Simulated Drought ◽  
Leaf Shedding ◽  
Clonal Variability

Selection for drought-tolerant clones has become a major challenge in rubber breeding programs undertaken to ensure the sustainability of natural rubber production, as rubber plantations are expanding in drought-prone areas. Xylem vulnerability to cavitation is a trait related to drought-induced mortality. It can be rapidly evaluated without subjecting plant materials to drought stress, making it useful in large-scale screening for drought tolerance in the near future. We first compared the most widely used techniques for measuring vulnerability to cavitation (air pressurization and Cavitron) on this species, and the effect of sample conditions (size, age and sunlight exposure), in order to ensure reliable analysis. Secondly, ten rubber clones were compared for their xylem vulnerability to cavitation in branches and petioles, and for other traits related to drought response, including stomatal response and leaf shedding occurring during a simulated drought. We also tested the plasticity of vulnerability to cavitation on two clones grown in three locations with contrasting precipitation regimes. We found no clonal variability and a small phenotypic plasticity for xylem vulnerability to cavitation in branches. However, clonal differences in xylem vulnerability to cavitation were found in petioles, and clones also showed differences in stomatal response and in leaf shedding behavior in response to a simulated drought. Our study suggests a genetic canalization for vulnerability to cavitation in organs critical for survival, such as branches, whereas there are clonal differences for traits related to drought avoidance: vulnerability to cavitation of petioles, leaf shedding behavior and stomatal response. The insights gained in this study for screening rubber tree clones for drought tolerance is also discussed. 

Seasonal variation in native hydraulic conductivity between two deciduous oak species

2019 ◽  
Vol 13 (1) ◽  
pp. 78-86
Author(s):  
Dilia Mota-Gutiérrez ◽  
Guadalupe Arreola-González ◽  
Rafael Aguilar-Romero ◽  
Horacio Paz ◽  
Jeannine Cavender-Bares ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Drought Tolerance ◽  
Water Use ◽  
Negative Impact ◽  
Dry Season ◽  
Turgor Loss Point ◽  
Xylem Vulnerability ◽  
Short Period ◽  
Quercus Species ◽  
Leaf Shedding

Abstract Aims Mechanisms of plant drought resistance include both tolerance and avoidance. Xylem vulnerability to embolism and turgor loss point are considered traits that confer tolerance, while leaf abscission and deciduousness characterizes the avoidance strategy. While these mechanisms are thought to trade-off expressing a continuum among species, little is known on how variation in the timing and duration of leaf shedding in response to drought affect the relationship between xylem and leaf tolerance. In the present study, we explored the extent to which drought tolerance differs between two oak (Quercus) species that exhibit different leaf shedding behaviours. Particularly, we predicted that Q. deserticola Trel., which loses leaves at the end of the dry season (late-deciduous) and is thus exposed to a greater risk of cavitation, would be more drought tolerant and more conservative in its water use than Q. laeta Liebm., which loses its leaves for only a short period of time in the middle of the dry season (brevideciduous). Methods The study was conducted in central Mexico in a single population of each of the two oak species, separated from each other by a distance of 1.58 km, and by an altitudinal difference of 191 m. Quercus deserticola (late deciduous) is more frequent down slope, while Q. laeta (brevideciduous) tends to occur at higher elevations along the gradient. We assessed seasonal differences (rainy versus dry season) in native stem hydraulic conductivity, and tested for variation in xylem vulnerability to cavitation, leaf water use and leaf turgor loss point between the two species. Important Findings The two oak species did not differ in traits conferring drought tolerance, including xylem vulnerability to embolism, leaf turgor loss point, or stomatal conductance. However, both species had different performance during the dry season; the brevideciduous species had lower negative impact in the xylem function than the late-deciduous species. Overall, seasonal changes in plant physiological performance between the two oak species were determined by a reduction in the canopy leaf area.

Intraspecific variation in drought susceptibility in Eucalyptus globulus is linked to differences in leaf vulnerability

2019 ◽  
Vol 46 (3) ◽  
pp. 286 ◽  
Author(s):  
Christopher J. Lucani ◽  
Timothy J. Brodribb ◽  
Greg Jordan ◽  
Patrick J. Mitchell
Keyword(s):  
Drought Tolerance ◽  
Intraspecific Variation ◽  
Eucalyptus Globulus ◽  
Forest Tree ◽  
Species Variation ◽  
Important Species ◽  
Phenotypic Differences ◽  
Hydraulic Failure ◽  
Xylem Vulnerability ◽  
Alternative Approach

Understanding intraspecific variation in the vulnerability of the xylem to hydraulic failure during drought is critical in predicting the response of forest tree species to climate change. However, few studies have assessed intraspecific variation in this trait, and a likely limitation is the large number of measurements required to generate the standard ‘vulnerability curve’ used to assess hydraulic failure. Here we explore an alternative approach that requires fewer measurements, and assess within species variation in leaf xylem vulnerability in Eucalyptus globulus Labill., an ecologically and economically important species with known genetic variation in drought tolerance. Using this approach we demonstrate significant phenotypic differences and evidence of plasticity among two provenances with contrasting drought tolerance.

scholarly journals Exogenous DCPTA Increases the Tolerance of Maize Seedlings to PEG-Simulated Drought by Regulating Nitrogen Metabolism-Related Enzymes

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 676 ◽  
Author(s):  
Tenglong Xie ◽  
Wanrong Gu ◽  
Congfeng Li ◽  
Jing Li ◽  
Shi Wei
Keyword(s):  
Drought Tolerance ◽  
Nitrite Reductase ◽  
Glutamate Synthase ◽  
Enzymatic Activities ◽  
Stable Gene ◽  
Maize Seedlings ◽  
Genes Encoding ◽  
Pair Comparisons ◽  
Physiological Indexes ◽  
Simulated Drought

2-(3,4-Dichlorophenoxy) triethylamine (DCPTA) regulates plant development; however, the molecular basis of this regulation is poorly understood. In this study, RNA sequencing (RNA-seq) analysis and physiological indexes of maize seedlings (three-leaf stage) treated with 15% polyethylene glycol (PEG) with/without DCPTA were investigated to explore the possible mechanism of exogenous DCPTA-improved drought tolerance. In the library pair comparisons of DCPTA vs. the control, PEG vs. the control, and PEG + DCPTA vs. PEG, totals of 19, 38 and 20 differentially expressed genes (DEGs) were classified as being involved in metabolic processes, respectively; totals of 5, 11, and 6 DEGs were enriched in the nitrogen (N) metabolic pathway, respectively. The genes encoding nicotinamide adenine dinucleotide-nitrate reductase (NADH-NR), ferredoxin-nitrite reductase (Fd-NiR), reduced ferredoxin- glutamate synthase (Fd-GOGAT), and chloroplastic glutamine synthetase (GS 2) were common in response to PEG-simulated drought stress with/without DCPTA treatment. Moreover, DCPTA maintained stable gene relative expression levels and protein abundances of NADH-NR, Fd-NiR, GS2, and Fd-GOGAT. Moreover, exogenous DCPTA partially mitigated PEG-simulated drought-induced reductions in the enzymatic activities of NR, nitrite reductase (NiR), glutamine synthase (GS), glutamine oxoglutarate aminotransferase (GOGAT), and transaminase, as well as in the contents of nitrate (NO3−), nitrite (NO2−) and soluble proteins and increases in the contents of ammonium (NH4+) and free amino acids. Together, our results indicate that exogenous DCPTA improved plant growth and drought tolerance by regulating N-mechanism enzymatic activities involved in transcription and enzymatic protein synthesis.

scholarly journals Delayed effect of drought on the xylem vulnerability to cavitation in Fagus sylvatica L.

2020 ◽  
Author(s):  
Stephane Herbette ◽  
Olivia Charrier ◽  
Herve Cochard ◽  
Tete Severien Barigah
Keyword(s):  
Drought Resistance ◽  
Environmental Conditions ◽  
European Beech ◽  
Severe Drought ◽  
Delayed Effect ◽  
Large Variability ◽  
Xylem Structure ◽  
Vulnerability To Cavitation ◽  
Xylem Vulnerability ◽  
Fagus Sylvatica L

Knowledge on variations of drought resistance traits is needed to predict the potential of trees to adapt to severe drought events expected to be more intense and frequent. Xylem vulnerability to cavitation is among the most important traits related to drought-induced mortality and exhibits a large variability between species. Acclimation of this trait to environmental conditions implies changes in the xylem structure and organization, leading previous studies to investigate its variations under conditions preserving growth. In European beech saplings, we assessed the effect of droughts of on the vulnerability to cavitation in branches that develop during recovery. The newly formed branches displayed lower vulnerability to cavitation in the plants that underwent the severest droughts leading to native embolism; the pressure that induces 50% loss of conductance being of -3.98 MPa in severely droughted plants whereas it was of -3.1 MPa in control plants, respectively. Although unexpected, these results argue for an acclimation, and not a weakening, of this trait to drought events.

scholarly journals Yellow nutsedge WRI3/4-like gene improves drought tolerance in Arabidopsis thaliana by promoting cuticular wax biosynthesis

2019 ◽  
Author(s):  
Chao Cheng ◽  
Shutong Hu ◽  
Yun Han ◽  
Di Xia ◽  
Bang-Lian Huang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Normal Growth ◽  
Growth Conditions ◽  
Cuticular Wax ◽  
Expression Data ◽  
Yellow Nutsedge ◽  
Transgenic Lines ◽  
Simulated Drought

Abstract Using RACE PCR, full length WRI1-like gene was amplified from yellow nutsedge. Conserved domain and phylogenetic analyses suggested it as WRI3/4-like gene. Tissue-specific expression data showed the highest expression in leaves, followed by roots while the lowest expression was detected in tuber. Transgenic Arabidopsis plants expressing nutsedge WRI3/4-like gene showed significantly improved tolerance to both PEG-simulated drought stress and real dehydration, compared with the wild type (WT). Under normal growth conditions, the expressions of key fatty acid biosynthesis genes was not significantly different between WT and transgenic lines, while the expressions of genes involved in cuticular wax biosynthesis was significantly higher in transgenic lines compared with the WT. The PEG-simulated drought stress did not induce any significant change in the expression of fatty acid and wax biosynthesis genes in WT plants, while the expression of fatty acid and wax biosynthesis genes was significantly increased in transgenic lines compared with WT as well as unstressed transgenic control. The expression of TAG1, the gene involved in triacylglycerol (TAG) accumulation, was significantly lower in the transgenic lines than that in the WT in normal growth conditions. Drought stress slightly decreased the expression of TAG1 in the WT, but significantly lowered it in transgenic lines compared with its unstressed transgenic control and WT. Consistent with gene expression data, the cuticular wax content in Arabidopsis leaves was significantly higher in the transgenic lines than in the WT, while the oil content was not significantly different. Our results indicated that WRI3/4-like gene from Cyperus esculentus improves drought tolerance in Arabidopsis probably by promoting cuticular wax biosynthesis and, hence, could be a valuable target for improving drought tolerance in crops through recombinant DNA technology.

scholarly journals Sugars from woody tissue photosynthesis reduce xylem vulnerability to cavitation

2017 ◽  
Vol 216 (3) ◽  
pp. 720-727 ◽  
Author(s):  
Niels J. F. De Baerdemaeker ◽  
Roberto Luis Salomón ◽  
Linus De Roo ◽  
Kathy Steppe
Keyword(s):  
Woody Tissue ◽  
Vulnerability To Cavitation ◽  
Xylem Vulnerability ◽  
Woody Tissue Photosynthesis

scholarly journals Soil Rather Than Xylem Vulnerability Controls Stomatal Response to Drought

2020 ◽  
Vol 25 (9) ◽  
pp. 868-880 ◽  
Author(s):  
Andrea Carminati ◽  
Mathieu Javaux
Keyword(s):  
Stomatal Response ◽  
Xylem Vulnerability
Sign in / Sign up

Export Citation Format

Share Document