Phenotypic plasticity versus ecotypic differentiation under recurrent summer drought in two drought‐tolerant pine species

In the South-west Australian Floristic Region, timing of rainfall is critical for successful seedling establishment, as is surviving the first year’s summer drought for population persistence. Predictions of a warmer, drier future, therefore, threaten the persistence of obligate seeding species. Here, we investigate the drought tolerance of two co-occurring Banksia (Proteaceae) species by withholding water in pots to different extents of soil drying. Seed was collected from high- and low-rainfall populations, to test for niche differentiation in water-use strategies at the species level, as well as population differentiation. On the basis of a more negative leaf water potential at minimal levels of stomatal conductance and quantum yield, B. coccinea was considered to be more drought tolerant than B. baxteri. This was supported at the anatomical level according to xylem-vessel attributes, with a higher estimated collapse pressure suggesting that B. coccinea is less vulnerable to xylem cavitation. Population contrasts were observed mainly for B. baxteri, with a lower leaf-expansion increment rate in the low-rainfall population providing for drought avoidance, which was reflected in a higher rate of survival than with the high-rainfall population in which 87.5% of plants showed complete leaf senescence. The implications of species differences in water-use strategies are that community dynamics may start to shift as the climate changes. Importantly, this shift may be population dependent. A systematic understanding of adaptive capacity will help inform the choice of population for use in revegetation programs, which may lead to increased resilience and persistence in the face of environmental change. The results of the present study suggest that should declines in B. baxteri populations be noted, revegetating with seed collected from the low-rainfall population may help improve the chances of this species surviving into the future.

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Phenotypic plasticity in the emission of terpenes by a threatened pine species (Pinus caribaea var. bahamensis): effects of scale infestation and environment

Forestry An International Journal of Forest Research ◽

10.1093/forestry/cpx013 ◽

2017 ◽

Vol 90 (4) ◽

pp. 553-560 ◽

Cited By ~ 3

Author(s):

P. W. C. Green ◽

M. A. Hamilton ◽

M. D. Sanchez ◽

R. Fang

Keyword(s):

Phenotypic Plasticity ◽

Pinus Caribaea ◽

Pine Species

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Leaf hydraulic vulnerability protects stem functionality under drought stress in Salvia officinalis

Functional Plant Biology ◽

10.1071/fp15324 ◽

2016 ◽

Vol 43 (4) ◽

pp. 370 ◽

Cited By ~ 18

Author(s):

Tadeja Savi ◽

Maria Marin ◽

Jessica Luglio ◽

Francesco Petruzzellis ◽

Sefan Mayr ◽

...

Keyword(s):

Water Potential ◽

Water Transport ◽

Salvia Officinalis ◽

Summer Drought ◽

Plant Organs ◽

Transport Efficiency ◽

Drought Tolerant ◽

Hydraulic Vulnerability ◽

Stem Water ◽

Salvia Officinalis L

Functional coordination between leaf and stem hydraulics has been proposed as a key trait of drought-resistant plants. A balanced water transport efficiency and safety of different plant organs might be of particular importance for plant survival in the Mediterranean climate. We monitored seasonal changes of leaf and stem water relations of Salvia officinalis L. in order to highlight strategies adopted by this species to survive in harsh environmental conditions. During summer drought, the water potential dropped below the turgor loss point thus reducing water loss by transpiration, whereas the photosynthetic efficiency remained relatively high. Leaves lost their water transport efficiency earlier than stems, although in both plant organs P50 (water potential inducing 50% loss of hydraulic conductivity) indicated surprisingly high vulnerability when compared with other drought-tolerant species. The fast recovery of leaf turgor upon restoration of soil water availability suggests that the reduction of leaf hydraulic conductance is not only a consequence of vein embolism, but cell shrinkage and consequent increase of resistance in the extra-xylem pathway may play an important role. We conclude that the drought tolerance of S. officinalis arises at least partly as a consequence of vulnerability segmentation.

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Ecotypic differentiation and phenotypic plasticity combine to enhance the invasiveness of the most widespread daisy in Chile, Leontodon saxatilis

Scientific Reports ◽

10.1038/s41598-017-01457-1 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 7

Author(s):

Irene Martín-Forés ◽

Marta Avilés ◽

Belén Acosta-Gallo ◽

Martin F. Breed ◽

Alejandro del Pozo ◽

...

Keyword(s):

Phenotypic Plasticity ◽

Ecotypic Differentiation

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Variable Effects on Growth and Defence Traits for Plant Ecotypic Differentiation and Phenotypic Plasticity along Elevation Gradients

10.1101/435453 ◽

2018 ◽

Author(s):

Moe Bakhtiari ◽

Ludovico Formenti ◽

Veronica Caggía ◽

Gaëtan Glauser ◽

Sergio Rasmann

Keyword(s):

Phenotypic Plasticity ◽

Growth Traits ◽

Chemical Defence ◽

Elevation Gradients ◽

Ecotypic Differentiation ◽

Chemical Defences ◽

Indole Glucosinolates ◽

Common Gardens ◽

Cardamine Pratensis ◽

Differential Contribution

AbstractAlong ecological gradients, ecotypes generally evolve as the result of local adaptation to a specific environment to maximize organisms’ fitness. Alongside ecotypic differentiation, phenotypic plasticity, as the ability of a single genotype to produce different phenotypes under different environmental conditions, can also evolve for favouring increased organisms’ performance in different environments. Currently, there is a lack in our understanding of how varying habitats may contribute to the differential contribution of ecotypic differentiation and plasticity in growth versus defence traits. Using reciprocal transplant-common gardens along steep elevation gradients, we evaluated patterns of ecotypic differentiation and phenotypic plasticity of two coexisting but unrelated plant species, Cardamine pratensis and Plantago major. For both species, we observed ecotypic differentiation accompanied by plasticity in growth related traits. Plants grew faster and produced more biomass when placed at low elevation. In contrast, we observed fixed ecotypic differentiation for defence and resistance traits. Generally, low elevation ecotypes produced higher chemical defences regardless of the growing elevation. Yet, some plasticity was observed for specific compounds, such as indole glucosinolates. We speculate that ecotypic differentiation in defence traits is maintained by costs of chemical defence production, while plasticity in growth traits is regulated by temperature driven growth response maximization.

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Modeling the forest dynamics of the Sierra Nevada under climate change using SORTIE-ND

Annals of Forest Science ◽

10.1007/s13595-021-01074-z ◽

2021 ◽

Vol 78 (3) ◽

Author(s):

Emily V. Moran ◽

Nikole Vannest ◽

Mélaine Aubry-Kientz

Keyword(s):

Climate Change ◽

Sierra Nevada ◽

Forest Dynamics ◽

Model Simulation ◽

Basal Area ◽

Stem Density ◽

Summer Drought ◽

Drought Period ◽

Drought Tolerant ◽

Tolerant Species

Abstract Key message Model simulation results suggest that forests in the Sierra Nevada mountains of California will tend to increase in density and basal area in the absence of fire over the next century, and that climate change will favor increases in drought-tolerant species. Context Climate change is projected to intensify the natural summer drought period for Mediterranean-climate forests. Such changes may increase tree mortality, change species interactions and composition, and impact ecosystem services. Aims To parameterize SORTIE-ND, an individual-based, spatially explicit forest model, for forests in the Sierra Nevada, and to model forest responses to climate change. Methods We use 3 downscaled GCM projections (RCP 8.5) to project forest dynamics for 7 sites at different elevations. Results Basal area and stem density tended to increase in the absence of fire. Climate change effects differed by species, with more drought-tolerant species such as Jeffrey pine (Pinus jeffreyi A.Murray bis) and black oak (Quercus kelloggii Newb.) exhibiting increases in basal area and/or density. Conclusion Increasing forest density may favor carbon sequestration but could increase the risk of high-severity fires. Future analyses should include improved parameterization of reproduction and interactions of disturbance with climate effects.

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Grafting cv. Grechetto Gentile Vines to New M4 Rootstock Improves Leaf Gas Exchange and Water Status as Compared to Commercial 1103P Rootstock

Agronomy ◽

10.3390/agronomy10050708 ◽

2020 ◽

Vol 10 (5) ◽

pp. 708 ◽

Cited By ~ 2

Author(s):

Tommaso Frioni ◽

Arianna Biagioni ◽

Cecilia Squeri ◽

Sergio Tombesi ◽

Matteo Gatti ◽

...

Keyword(s):

Water Stress ◽

Gas Exchange ◽

Water Use ◽

Leaf Gas Exchange ◽

Water Status ◽

Stomatal Closure ◽

Leaf Water ◽

Summer Drought ◽

Co2 Uptake ◽

Drought Tolerant

M4 is a relatively new rootstock that was selected for increased resilience of vineyards across hot regions where meteorological drought is often coupled to water scarcity. However, M4 has thus far been tested only against water-stress sensitive rootstocks. Against this backdrop, the aim of the present work is to examine the water status and gas exchange performances of vines grafted to M4 in comparison to those of vines grafted to a commercial stock that is drought-tolerant, 1103 Paulsen (1103P), under a progressive water deficit followed by re-watering. This study was undertaken on Grechetto Gentile, a cultivar that is renowned for its rather conservative water use (near-isohydric behavior). While fifty percent of both grafts were fully irrigated (WW), the remaining underwent progressive water stress by means of suspending irrigation (WS). Soil and leaf water status, as well as leaf gas exchanges, along with chlorophyll fluorescence, were followed daily from 1 day pre-stress (DOY 176) until re-watering (DOY 184). Final leaf area per vine, divided in main and lateral contribution, was also assessed. While 1103P grafted vines manifested higher water use under WW conditions, progressive stress evidenced a faster water depletion by 1103P, which also maintained slightly more negative midday leaf water potential (Ψleaf) as compared to M4 grafted plants. Daily gas exchange readings, as well as diurnal assessment performed at the peak of stress (DOY 183), also showed increased leaf assimilation rates (A) and water use efficiency (WUE) in vines grafted on M4, which were also less susceptible to photosynthetic downregulation. Dynamic of stomatal closure targeted at 90% reduction of leaf stomatal conductance showed a similar behavior among rootstocks since the above threshold was reached by both at Ψleaf of about −1.11 MPa. The same fractional reduction in leaf A was reached by vines grafted on M4 at a Ψleaf of −1.28 MPa vs. −1.10 MPa measured in 1103P, meaning that using M4 as a rootstock will postpone full stomatal closure. While mechanisms involved in improved CO2 uptake in M4-grafted vines under moderate-to-severe stress are still unclear, our data support the hypothesis that M4 might outscore the performance of a commercial drought-tolerant genotype (1103P) and can be profitably used as a tool to improve the resilience of vines to summer drought.

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