scholarly journals Physiological Responses to Abiotic and Biotic Stress in Forest Trees

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 711 ◽  
Author(s):  
Andrea Polle ◽  
Heinz Rennenberg

Forests fulfill important ecological functions by sustaining nutrient cycles and providing habitats for a multitude of organisms. They further deliver ecosystem services such as carbon storage, protection from erosion, and wood as an important commodity. Trees have to cope in their environment with a multitude of natural and anthropogenic forms of stress. Resilience and resistance mechanisms to biotic and abiotic stresses are of special importance for long-lived tree species. Since trees exist for many decades or even centuries on the same spot, they have to acclimate their growth and reproduction to constantly changing atmospheric and pedospheric conditions. In this special issue, we invited contributions addressing the physiological responses of forest trees to a wide array of different stress factors. Among the eighteen papers published, seventeen covered drought or salt stress as major environmental cues, highlighting the relevance of this topic in times of climate change. Only one paper studied cold stress [1]. The dominance of drought and salt stress studies underpins the need to understand tree responses to these environmental threats from the molecular to the ecophysiological level. The papers contributing to this Special Issue cover these scientific aspects in different areas of the globe and encompass conifers as well as broadleaf tree species. In addition, two studies deal with bamboo (Phyllostachys sp., [1,2]). Bamboo, although botanically belonging to grasses, was included because its ecological functions and applications are similar to those of trees.

2021 ◽  
Vol 12 ◽  
Author(s):  
Shumei Fang ◽  
Xue Hou ◽  
Xilong Liang

As two coexisting abiotic stresses, salt stress and alkali stress have severely restricted the development of global agriculture. Clarifying the plant resistance mechanism and determining how to improve plant tolerance to salt stress and alkali stress have been popular research topics. At present, most related studies have focused mainly on salt stress, and salt-alkali mixed stress studies are relatively scarce. However, in nature, high concentrations of salt and high pH often occur simultaneously, and their synergistic effects can be more harmful to plant growth and development than the effects of either stress alone. Therefore, it is of great practical importance for the sustainable development of agriculture to study plant resistance mechanisms under saline-alkali mixed stress, screen new saline-alkali stress tolerance genes, and explore new plant salt-alkali tolerance strategies. Herein, we summarized how plants actively respond to saline-alkali stress through morphological adaptation, physiological adaptation and molecular regulation.


2020 ◽  
Vol 47 (9) ◽  
pp. 779
Author(s):  
Débora di Francescantonio ◽  
Mariana Villagra ◽  
Guillermo Goldstein ◽  
Paula I. Campanello

Frost and drought are key stress factors limiting the growth and distribution of tree species. Resistance to stress involves energy costs that may result in trade-offs between different functional traits. Structures or mechanisms that can help to withstand stress imply differences in the carbon economy of the species. Although adaptive responses to frost and drought resistance are usually of a similar nature, they are rarely assessed simultaneously. We investigated these resistance mechanisms in 10 canopy tree species coexisting in the semi-deciduous subtropical forests of northern Argentina. We measured leaf lifespan, anatomical, photosynthetic and water relations traits and performed a thermal analysis in leaves to determined ice nucleation and tissue damage temperatures. Our results showed that evergreen and deciduous species have different adaptive responses to cope with freezing temperatures and water deficits. Evergreen species exhibited cold tolerance, while deciduous species were more resistant to hydraulic dysfunction and showed greater water transport efficiency. Further research is needed to elucidate resistance strategies to stress factors at the whole tree- and stand level, and possible links with hydraulic safety and efficiency among different phenological groups. This will allow us to predict the responses of subtropical forest species to changes in environmental conditions under climate change scenarios.


2021 ◽  
Vol 13 (15) ◽  
pp. 8369
Author(s):  
Chintan Kapadia ◽  
R. Z. Sayyed ◽  
Hesham Ali El Enshasy ◽  
Harihar Vaidya ◽  
Deepshika Sharma ◽  
...  

Salinity significantly impacts the growth, development, and reproductive biology of various crops such as vegetables. The cultivable area is reduced due to the accumulation of salts and chemicals currently in use and is not amenable to a large extent to avoid such abiotic stress factors. The addition of microbes enriches the soil without any adverse effects. The effects of microbial consortia comprising Bacillus sp., Delftia sp., Enterobacter sp., Achromobacter sp., was evaluated on the growth and mineral uptake in tomatoes (Solanum Lycopersicum L.) under salt stress and normal soil conditions. Salinity treatments comprising Ec 0, 2, 5, and 8 dS/m were established by mixing soil with seawater until the desired Ec was achieved. The seedlings were transplanted in the pots of the respective pH and were inoculated with microbial consortia. After sufficient growth, these seedlings were transplanted in soil seedling trays. The measurement of soil minerals such as Na, K, Ca, Mg, Cu, Mn, and pH and the Ec were evaluated and compared with the control 0 days, 15 days, and 35 days after inoculation. The results were found to be non-significant for the soil parameters. In the uninoculated seedlings’ (control) seedling trays, salt treatment significantly affected leaf, shoot, root dry weight, shoot height, number of secondary roots, chlorophyll, and mineral contents. While bacterized seedlings sown under saline soil significantly increased leaf (105.17%), shoot (105.62%), root (109.06%) dry weight, leaf number (75.68%), shoot length (92.95%), root length (146.14%), secondary roots (91.23%), and chlorophyll content (−61.49%) as compared to the control (without consortia). The Na and K intake were higher even in the presence of the microbes, but the beneficial effect of the microbe helps plants sustain in the saline environment. The inoculation of microbial consortia produced more secondary roots, which accumulate more minerals and transport substances to the different parts of the plant; thus, it produced higher biomass and growth. Results of the present study revealed that the treatment with microbial consortia could alleviate the deleterious effects of salinity stress and improve the growth of tomato plants under salinity stress. Microbial consortia appear to be the best alternative and cost-effective and sustainable approach for managing soil salinity and improving plant growth under salt stress conditions.


Author(s):  
Muhammad Talha Bin Yousaf ◽  
Muhammad Farrakh Nawaz ◽  
Muhammad Zia ur Rehman ◽  
Sadaf Gul ◽  
Ghulam Yasin ◽  
...  

2021 ◽  
Vol 164 ◽  
pp. 10-20
Author(s):  
Wancong Yu ◽  
Yue Yu ◽  
Ceng Wang ◽  
Zhijun Zhang ◽  
Zhaohui Xue

2018 ◽  
Vol 42 (2) ◽  
Author(s):  
Daniele Maria Marques ◽  
Adriano Bortolotti Silva ◽  
José Ricardo Mantovani ◽  
Dalvana Sousa Pereira ◽  
Thiago Corrêa Souza

ABSTRACT Copper (Cu) is an essential micronutrient for plants. However, when in excess, it becomes phytotoxic. In this context, the objective of this study was to evaluate the growth and physiological responses of tree species exposed to different copper concentrations in the soil. Three experiments were carried out, one for each forest species under study: Myroxylon peruiferum ("Óleo Bálsamo"), Hymenaea courbaril ("Jatobá") and Peltophorum dubium ("Canafístula"), with the same doses of copper (0, 50, 100, 200 and 400 mg kg-1). The experimental design was in randomized blocks (DBC), with five copper concentrations and four replicates. The plants were grown on soil substrate packed in 8-dm3 pots and kept in a greenhouse for 90 days. Biometric measurements, chlorophyll, antioxidant enzymes and copper content in tissues were evaluated. Copper did not influence the vegetative growth of the species studied. The content of chlorophyll "a" was reduced with increasing copper concentrations in the soil. H. courbaril had 56 to 92% copper retained in the roots, and the same behavior was observed for P. dubium (77-91%) and M. peruiferum (19-64%). In the three species studied, there was copper bioaccumulation, mainly in the roots, possibly as a metal tolerance strategy, preserving the most active tissues and the photosynthetic machinery. Cu translocation from roots to shoot was very restricted in all species. This behavior, associated with the increase in the activity of some antioxidant enzymes in plants, may indicate the phytoremediation potential of the studied species.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 345
Author(s):  
Simona Carfagna ◽  
Giovanna Salbitani ◽  
Michele Innangi ◽  
Bruno Menale ◽  
Olga De Castro ◽  
...  

Pancratium maritimum (Amaryllidaceae) is a bulbous geophyte growing on coastal sands. In this study, we investigated changes in concentrations of metabolites in the root and leaf tissue of P. maritimum in response to mild salt stress. Changes in concentrations of osmolytes, glutathione, sodium, mineral nutrients, enzymes, and other compounds in the leaves and roots were measured at 0, 3, and 10 days during a 10-day exposure to two levels of mild salt stress, 50 mM NaCl or 100 mM NaCl in sandy soil from where the plants were collected in dunes near Cuma, Italy. Sodium accumulated in the roots, and relatively little was translocated to the leaves. At both concentrations of NaCl, higher values of the concentrations of oxidized glutathione disulfide (GSSG), compared to reduced glutathione (GSH), in roots and leaves were associated with salt tolerance. The concentration of proline increased more in the leaves than in the roots, and glycine betaine increased in both roots and leaves. Differences in the accumulation of organic osmolytes and electron donors synthesized in both leaves and roots demonstrate that osmoregulatory and electrical responses occur in these organs of P. maritimum under mild salt stress.


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