Heat shock effects on germination and seed survival of five woody species from the Chaco region

Flora ◽  
2021 ◽  
Vol 275 ◽  
pp. 151751
Author(s):  
Amalia Valeria Ibañez Moro ◽  
Sandra Josefina Bravo ◽  
Nelly Roxana Abdala ◽  
Fabian Borghetti ◽  
Adalgisa Maria Chaib ◽  
...  
Keyword(s):  
Heat Shock ◽  
Woody Species ◽  
Seed Survival ◽  
Chaco Region

A comparative assessment of plant flammability through a functional approach: The case of woody species from Argentine Chaco region

2019 ◽  
Vol 44 (8) ◽  
pp. 1416-1429 ◽  
Author(s):  
Ana Carolina Santacruz-García ◽  
Sandra Bravo ◽  
Florencia del Corro ◽  
Fernando Ojeda
Keyword(s):  
Woody Species ◽  
Functional Approach ◽  
Comparative Assessment ◽  
Chaco Region

Fire regime of a Elionorus muticus Spreng. savanna, western Chaco region, Argentina

2001 ◽  
Vol 10 (1) ◽  
pp. 65 ◽  
Author(s):  
Sandra Bravo ◽  
Carlos Kunst ◽  
Ana Gimenez ◽  
Graciela Moglia
Keyword(s):  
Cross Sections ◽  
Native Species ◽  
Fire History ◽  
Fire Regime ◽  
Woody Species ◽  
Fire Frequency ◽  
Grass Species ◽  
Fire Scars ◽  
Chaco Region ◽  
Native Woody Species

Our objective was to assess the current fire regime of a 600 ha savanna dominated by the grass species Elionorus muticus Spreng., located in Santiago del Estero Province, north-western Chaco region, Argentina. The degree of tolerance of some native woody species to fire, the fire mean fire frequency (FF), and Weibull median probability (WMPI) were evaluated. Sampling sites were located in the ecotone between the savanna and the surrounding forests. A database was developed from fire scars found in cross sections of native tree and shrub species, cut at different heights above ground; that covered the recent 70 years of fire history (1925–1996). Results indicate that the savanna has a mean FF of 0.179 fires year–1 and an FI = 3 years. The mean height of fire scars found in trees and shrubs which indicate medium to high fireline intensities with flame lengths larger than 1 m are frequent in the savanna. Native species have different degrees of tolerance: Aspidosperma quebracho blanco (tree) and Schinopsis quebracho colorado (tree) are more tolerant to fire than Acacia furcatispina (shrub) and A. aroma (shrub). Bark thickness of the tree species (1–1.5 cm in mature individuals) allows them to withstand the frequent, high intensity fires of the savanna.

scholarly journals Effects of prescribed fires on the survival and release of seeds of Kielmeyera coriacea (Spr.) Mart. (Clusiaceae) in savannas of Central Brazil

2008 ◽  
Vol 20 (3) ◽  
pp. 197-204 ◽  
Author(s):  
Paulo Cirne ◽  
Heloisa Sinátora Miranda
Keyword(s):  
Prescribed Fire ◽  
Germination Rate ◽  
Woody Species ◽  
Sensu Stricto ◽  
Dry Season ◽  
Prescribed Fires ◽  
Seed Survival ◽  
Central Brazil ◽  
Savanna Vegetation ◽  
Kielmeyera Coriacea

Effects of prescribed fires on survival and release of seeds of the woody species Kielmeyera coriacea (Clusiaceae) were investigated in two plots of cerrado sensu stricto, a savanna vegetation of Central Brazil. The first plot was burnt in June, at the beginning of the dry season, and the second in August, in the middle of the dry season. Seed survival was measured after fire in both areas and related to internal and external fruit temperatures measured during the June fire. The proportion of open fruits per individual of K. coriacea was also assessed at two-week intervals. Maximum external temperatures during fire (393 to 734ºC) were strongly reduced inside the fruits (61 to 63ºC). Before the June fire, the majority of the fruits were closed in both plots. Most fruits in the June plot opened within two weeks following the burning while, in the same period, most fruits remained closed in the August plot. Fifteen days after the prescribed fire in the August plot most fruits opened, as observed in the June plot. No germination was observed in seeds from closed fruits collected before the fire, while those from fruits that were closed during the burning showed a high mean germination rate (June = 79 ± 12%; August = 69 ± 14%). The results indicate that fruits of K. coriacea are good insulators for seeds during fires and that seed release is anticipated independently of the burning season.

scholarly journals Could Fire Severity Promotes the Biosynthesis of Bioactive Compounds as a Strategy to Improve Plant Survival?

2020 ◽  
Vol 3 (1) ◽  
pp. 19
Author(s):  
Ana Carolina Santacruz-García ◽  
Mónica Azucena Nazareno ◽  
Sandra Bravo
Keyword(s):  
Secondary Metabolites ◽  
Fire Severity ◽  
Woody Species ◽  
Plant Response ◽  
Fire Season ◽  
Natural Environments ◽  
Spectrophotometric Methods ◽  
Chaco Region ◽  
Response To Stress ◽  
Shrubby Species

Fire has effects on diverse aspects of plant functioning and development, many of them linked to survival. However, the response of native vegetation to this disturbance possibly reveals a plant strategy to tolerate fire linked to the biosynthesis of compounds such as chlorophylls and secondary metabolites. The aim of this study was to evaluate whether fire severity could promote biochemical tolerance to fire by influencing the biosynthesis of chemical compounds. To test this, six woody species from the Chaco region were exposed to an experimental burn of medium severity at the end of fire season in the study area. In this burn, individual plots for each plant were established. Fire severity was estimated visually as the burnt biomass of each plant, which was considered as the percentage of the loss of aboveground biomass. Then, the biochemical plant response to fire was studied, through the changes in the concentration of photosynthetic pigments (chlorophyll and carotenoids), and secondary metabolites (phenolic compounds and tannins). The metabolite quantification was carried out by using spectrophotometric methods. As a result, a strong correlation was found between the biosynthesis of metabolites in response to fire and the amount of burnt biomass during the experimental burns. This correlation could be considered as an indicator of the burnt plant response to stress. In our results, shrubby species showed both the higher amount of burnt biomass and the enhanced biosynthesis of compounds in the resprouts post-fire, which could be related to the capacity of these species to be established in disturbed environments. Our study provides new insights into the understanding of the plant strategies to fire tolerance and resilience in natural environments.

Provenance matters: variability under saline stress in young plants of four populations of a Prosopis (mesquite) species from dry forests of Argentina

2021 ◽  
Author(s):  
Paula Venier ◽  
Guillermo Funes ◽  
Ingrid Teich ◽  
Diego López Lauenstein ◽  
Ramiro Lascano
Keyword(s):  
Forest Restoration ◽  
Stress Condition ◽  
Woody Species ◽  
Growth Conditions ◽  
Stem Diameter ◽  
Saline Stress ◽  
Dry Forests ◽  
Salt Stress Condition ◽  
Physiological Variables ◽  
Chaco Region

Planting of native perennial woody species tolerant to variable salt concentrations can facilitate the recovery of degraded dry forests. The objective was to evaluate and compare the response to saline stress on experimentally controlled conditions of young plants from four provenances of Prosopis alba, a mesquite species useful for restoration plans. They were from different localities of the Chaco Region of Argentina (Santiago del Estero, Chaco, Formosa and Salta) and were evaluated for 45 days under greenhouse controlled growth conditions at 0, 100 and 300 mM NaCl. We measured variables associated with growth, photosynthesis and redox state. The imposed salt stress condition did not cause plant death in any provenance. However, salinity produced a strong effect on growth and physiological variables of all provenances. Salta provenance was associated to higher net values of biomass and stem diameter. Chaco registered the greatest relative values of height and stem diameter, indicating a higher salinity tolerance than the other provenances; also it produced more antioxidants, to cope with the oxidative stress associated to saline stress. Chaco and Salta could be the most promising provenances to use in restoration plans of dry forests in areas with saline soils in the Chaco region. We emphasize the importance of use different provenances in forest restoration for a more successful system recovery.

scholarly journals Recent Advances in the Roles of HSFs and HSPs in Heat Stress Response in Woody Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Fengxia Tian ◽  
Xiao-Li Hu ◽  
Tao Yao ◽  
Xiaohan Yang ◽  
Jin-Gui Chen ◽  
...  
Keyword(s):  
Stress Response ◽  
Heat Shock ◽  
Woody Plants ◽  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Elevated Temperatures ◽  
Extreme Temperature ◽  
Woody Species ◽  
Future Research ◽  
Continuous Increase

A continuous increase in ambient temperature caused by global warming has been considered a worldwide threat. As sessile organisms, plants have evolved sophisticated heat shock response (HSR) to respond to elevated temperatures and other abiotic stresses, thereby minimizing damage and ensuring the protection of cellular homeostasis. In particular, for perennial trees, HSR is crucial for their long life cycle and development. HSR is a cell stress response that increases the number of chaperones including heat shock proteins (HSPs) to counter the negative effects on proteins caused by heat and other stresses. There are a large number of HSPs in plants, and their expression is directly regulated by a series of heat shock transcription factors (HSFs). Therefore, understanding the detailed molecular mechanisms of woody plants in response to extreme temperature is critical for exploring how woody species will be affected by climate changes. In this review article, we summarize the latest findings of the role of HSFs and HSPs in the HSR of woody species and discuss their regulatory networks and cross talk in HSR. In addition, strategies and programs for future research studies on the functions of HSFs and HSPs in the HSR of woody species are also proposed.

scholarly journals Expression of “Rooting” Genes iaaM and rolB Under Regulatory Promoters in Tobacco

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 481E-482
Author(s):  
Wayne A. Sargent ◽  
Zong-Ming Cheng
Keyword(s):  
Heat Shock ◽  
Root Formation ◽  
Woody Species ◽  
Gus Expression ◽  
Gus Gene ◽  
Hybrid Aspen ◽  
Inducible Promoters ◽  
The North ◽  
Central United States ◽  
Genetically Improved

Hybrid aspen is a major source of fiber in the north-central United States. One major problem for utilizing genetically improved aspen, and a variety of other woody species, is the difficulty in rooting hardwood cuttings. The objective of this project was to construct and confirm the function of genetic transformation vectors with two rooting genes (iaaM from Agrobacterium tumefaciens and rolB from A. rhizogenes) using three promoters (CaMV35S, soybean heat shock-inducible and poplar wound-inducible promoters). The gene constructs can be used to transform aspen for improvement of rooting hardwood cuttings and to elucidate rooting mechanisms. Each of these six gene constructs was inserted contiguously upstream from the promoter-less-glucuronidase (GUS) gene in the plasmid pBI 101. The engineered plasmids were transformed into A. tumefaciens strain LBA 4404 by electroporation. The functions of the genes were confirmed by transforming Nicotiana tabacum with these constructs. In plants transformed with iaaM and rolB under the CaMV35S promoter, the GUS gene expressed constitutively. These plants were also morphologically abnormal, with callus (and sometimes root) formation on stem tissue. The plants transformed with heat shock and Win6 constructs had no root formation and little or no GUS expression, without induction. After induction with heat shock (42°C for 1 hr per day for 7 days) or wounding (wounding the plants daily for 7 days), root formation occurred and GUS expression increased significantly with each gene, respectively. No roots developed in the non-transformed control shoots. The transformed plants with the regulatory promoters appeared morphologically normal. These constructs are currently being tested in hybrid aspen.

Seed germination of herbaceous and woody species of the Sudanian savanna-woodland in response to heat shock and smoke

2008 ◽  
Vol 256 (3) ◽  
pp. 462-470 ◽  
Author(s):  
Sidzabda Djibril Dayamba ◽  
Mulualem Tigabu ◽  
Louis Sawadogo ◽  
Per Christer Oden
Keyword(s):  
Heat Shock ◽  
Seed Germination ◽  
Woody Species ◽  
Savanna Woodland

Two-hundred-year seed survival of Leucospermum and two other woody species from the Cape Floristic region, South Africa

2007 ◽  
Vol 17 (2) ◽  
pp. 73-79 ◽  
Author(s):  
Matthew I. Daws ◽  
Jennifer Davies ◽  
Elly Vaes ◽  
Roelof van Gelder ◽  
Hugh W. Pritchard
Keyword(s):  
South Africa ◽  
Seed Coat ◽  
Woody Species ◽  
Cape Floristic Region ◽  
Ex Situ ◽  
Term Survival ◽  
Long Term Survival ◽  
Seed Survival ◽  
Impermeable Seed Coat

AbstractThe ability of orthodox seeds to survive long-term dry storage is a key prerequisite for ex situ seed conservation in genebanks. However, only a few credible observations of seed survival for ≥ 200 years have been reported. In this paper, seed survival is shown for three species under suboptimal storage conditions for a documented time of ≥ 203 years and carbon dated at 218–270 years. Two species that germinated are in the Fabaceae (Liparia sp. and Acacia sp.). A water-impermeable seed coat, and hence an inability to equilibrate with ambient relative humidity, may contribute to long-term survival of these species. The third species that germinated (Leucospermum sp.) does not have a water-impermeable seed coat, and long-term survival may be linked to an oxygen-impermeable barrier in the seed. These results for species from the Cape Floristic Region, South Africa, suggest adaptation for extreme longevity in seeds of species of seasonally dry, Mediterranean environments.

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