Alteration of element contents in guard cells of Norway spruce (Picea abies) subjected to ozone fumigation and (or) water stress: X-ray microanalysis study

1994 ◽  
Vol 72 (1) ◽  
pp. 86-92 ◽  
Author(s):  
D. Le Thiec ◽  
C. Rose ◽  
J. P. Garrec ◽  
D. Laffray ◽  
P. Louguet ◽  
...  

Two clones of Norway spruce Picea abies (L.) Karst. (Gerardmer clone and Istebna clone) were subjected to an ozone-enriched atmosphere. The X-ray microanalysis of elements present in the guard cells showed a decrease in potassium for the Gerardmer clone along with a larger closing of guard cells and an increase in calcium contents; for the Istebna clone, ozone did not affect these contents. When a drought stress was applied, an increase in calcium content of guard cells of the Istebna clone was also found. However, the potassium content was smaller in this case for the two clones and could well be due to stomatal closure. When ozone and drought stress were applied together, the potassium content in the Istebna clone was not affected, but for the Gerardmer clone, ozone reduced the decrease in potassium content that occurred as drought stress developed. However, calcium (and manganese) content increased significantly when the Gerardmer clone was exposed to ozone. It seems likely that the Gerardmer clone is sensitive to ozone and when subjected to a drought stress this sensitivity is increased. For the Istebna clone, the resistance to ozone is unaffected by the drought stress treatment. The Istebna clone, however, seems sensitive to drought. These characteristic responses in the two different Norway spruce clones are probably due to genetic differences and may explain the contradictory observations in the response of the stomata during the simultaneous implementation of the complex stresses. Key words: Picea abies, guard cells, ozone, drought stress, X-ray microanalysis, elements.

Author(s):  
Xenia Hao-Yi Yeoh ◽  
Blessing Durodola ◽  
Kathrin Blumenstein ◽  
Eeva Terhonen

The major threats to the sustainable supply of forest tree products are adverse climate, pests and diseases. Climate change, exemplified by increased drought, poses a unique threat to global forest health. This is attributed to the unpredictable behavior of forest pathosystems, which can favor fungal pathogens over the host under persistent drought stress conditions in the future. Currently, the effects of drought on tree resistance against pathogens are hypothetical, thus research is needed to identify these correlations. Norway spruce (Picea abies) is one of the most economically important tree species in Europe, and is considered highly vulnerable to changes in climate. Dedicated experiments to investigate how disturbances will affect the Norway spruce - Heterobasidion sp. pathosystem are important, in order to develop different strategies to limit the spread of H. annosum s.l. under the predicted climate change. Here, we report a transcriptional study to compare Norway spruce gene expressions to evaluate the effects of water availability and the infection of Heterobasidion parviporum. We performed inoculation studies of three-year-old saplings in a greenhouse (purchased from a nursery). Norway spruce saplings were treated in either high (+) or low (-) water groups: high water group received double the water amount than the low water group. RNA was extracted and sequenced. Similarly, we quantified gene expression levels of candidate genes in biotic stress and jasmonic acid (JA) signaling pathways using qRT-PCR, through which we discovered a unique preferential defense response of H. parviporum-infected Norway spruce under drought stress at the molecular level. Disturbances related to water availability, especially low water conditions can have negative effects on the tree host and benefit the infection ability of the pathogens in the host. From our RNA-seq analysis, 114 differentially expressed gene regions were identified between high (+) and low (-) water groups under pathogen attack. None of these gene pathways were identified to be differentially expressed from both non-treated and mock-control treatments between high (+) and low (-) water groups. Finally, only four genes were found to be associated with drought in all treatments.


2019 ◽  
Vol 116 (11) ◽  
pp. 5015-5020 ◽  
Author(s):  
Chenchen Zhao ◽  
Yuanyuan Wang ◽  
Kai Xun Chan ◽  
D. Blaine Marchant ◽  
Peter J. Franks ◽  
...  

Chloroplast retrograde signaling networks are vital for chloroplast biogenesis, operation, and signaling, including excess light and drought stress signaling. To date, retrograde signaling has been considered in the context of land plant adaptation, but not regarding the origin and evolution of signaling cascades linking chloroplast function to stomatal regulation. We show that key elements of the chloroplast retrograde signaling process, the nucleotide phosphatase (SAL1) and 3′-phosphoadenosine-5′-phosphate (PAP) metabolism, evolved in streptophyte algae—the algal ancestors of land plants. We discover an early evolution of SAL1-PAP chloroplast retrograde signaling in stomatal regulation based on conserved gene and protein structure, function, and enzyme activity and transit peptides of SAL1s in species including flowering plants, the fern Ceratopteris richardii, and the moss Physcomitrella patens. Moreover, we demonstrate that PAP regulates stomatal closure via secondary messengers and ion transport in guard cells of these diverse lineages. The origin of stomata facilitated gas exchange in the earliest land plants. Our findings suggest that the conquest of land by plants was enabled by rapid response to drought stress through the deployment of an ancestral SAL1-PAP signaling pathway, intersecting with the core abscisic acid signaling in stomatal guard cells.


Author(s):  
Gerhard Wieser ◽  
Wilhelm M. Havranek

SynopsisLittle is known about ozone (O3) effects on adult trees in the field, where ecophysiological parameters control pollutant uptake. It was the goal of this study to examine how ambient and above ambient O3 concentrations affect gas exchange of mature Norway spruce (Picea abies (L.) Karst.). Therefore, twigs were enclosed in chambers and exposed to different O3 concentrations for one and two seasons over three years. During winter periods twigs were maintained under ambient conditions. Data from the shade crown of spruce trees at 1000 m a.s.l. are presented. After one and two fumigation periods no clear treatment effects on gas exchange were observed in twigs fumigated with O3 concentrations ranging from zero up to ambient (A) + 60 ppb. However, O3 at 90 ppb reduced photosynthesis and conductance. CO2 response curves indicated that in A + 90 twigs the efficiency of CO2 uptake was diminished. Observed losses in Pn of A + 90 twigs were greater than reductions in conductance indicating that stomatal closure alone did not limit CO2 uptake. We conclude that ambient and slightly above ambient O3 concentrations do not alter gas exchange of mature Norway spruce. Therefore, suppositions on O3 damage on mature spruce trees should be critically questioned.


1997 ◽  
Vol 136 (2) ◽  
pp. 265-275 ◽  
Author(s):  
P. E. KARLSSON ◽  
E. L. MEDIN ◽  
G. WALLIN ◽  
G. SELLDEN ◽  
L. SKARBY

1994 ◽  
Vol 72 (12) ◽  
pp. 1835-1842 ◽  
Author(s):  
Michèle Ridolfi ◽  
Jean Pierre Garrec ◽  
Philippe Louguet ◽  
Daniel Lafray

The effects of potassium or calcium deficiency on stomatal functioning were investigated in Vicia faba L. plants grown hydroponically. In the leaves of plants grown with 1 mM K+, stomatal opening occurred in light with either normal or CO2-free air; K+ and C1− accumulations in guard cells were similar to those of the control plants grown with 5 mM K+. With the zero K+ treatment, stomatal apertures were not affected, while K+ and Cl− guard cell concentrations fell to 30% of the control values. These results may indicate that other solutes contribute to the lowering of osmotic potential during opening. Stomata of calcium-deficient plants remained fully open in darkness, whereas abscisic acid (ABA) supply induced a partial stomatal closing movement. Therefore, calcium deficiency inhibited the process(es) linked with the perception of darkness and stomatal closure. On the other hand, stomatal sensitivity to ABA was only partially affected. Key words: stomatal aperture, potassium, calcium, X-ray microanalysis.


2009 ◽  
Vol 30 (2) ◽  
pp. 205-213 ◽  
Author(s):  
L. Ditmarova ◽  
D. Kurjak ◽  
S. Palmroth ◽  
J. Kmet ◽  
K. Strelcova

Author(s):  
Gabrielle Donnay ◽  
J. F. Schairer ◽  
J. D. H. Donnay

SummaryPublished chemical analyses demonstrate that the nepheline formula should be written KxNayCaz□s-(x+y+z)Alx+y+2zSi16-(x+y+2z)O32, where □ stands for vacant sites. X-ray data are presented for the nepheline phase in four binary systems: Ne-CaAl2O4, Ne-An, Ne-Ab, Ne-Kp. Only in two of these systems do the cell-dimensions change with composition. In the first one, the cell-volume V increases linearly with increasing calcium content; in the last one, two singularities in the curve of V against x divide the phase Na8-xKxAl8Si8O32 into three subphases: subpotassic (0 < x < 0·25), mediopotassic (0·25 < x < 2·00), and perpotassic (2·00 < x < 4·73). Only in the subpotassic range are both high- and low-temperature forms found. Twenty-eight natural nephelines, for which chemical analyses and X-ray data are available in the literature, show that only the potassium content affects cell-dimensions. Although all analysed natural nephelines fall outside the subpotassic range, the re-examination of a Monte Somma specimen studied by Bannister (1931) reveals a few euhedral crystals of subpotassic nepheline in a mediopotassic phase.


Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1379
Author(s):  
Xenia Hao-Yi Yeoh ◽  
Blessing Durodola ◽  
Kathrin Blumenstein ◽  
Eeva Terhonen

The major threats to the sustainable supply of forest tree products are adverse climate, pests and diseases. Climate change, exemplified by increased drought, poses a unique threat to global forest health. This is attributed to the unpredictable behavior of forest pathosystems, which can favor fungal pathogens over the host under persistent drought stress conditions in the future. Currently, the effects of drought on tree resistance against pathogens are hypothetical, thus research is needed to identify these correlations. Norway spruce (Picea abies (L.) H. Karst.) is one of the most economically important tree species in Europe and is considered highly vulnerable to changes in climate. Dedicated experiments to investigate how disturbances will affect the Norway spruce—Heterobasidion sp. pathosystem are important, in order to develop different strategies to limit the spread of H. annosum s.l. under the predicted climate change. Here, we report a transcriptional study to compare Norway spruce gene expressions to evaluate the effects of water availability and the infection of Heterobasidion parviporum. We performed inoculation studies of three-year-old saplings in a greenhouse (purchased from a nursery). Norway spruce saplings were treated in either high (+) or low (−) water groups: high water group received double the water amount than the low water group. RNA was extracted and sequenced. Similarly, we quantified gene expression levels of candidate genes in biotic stress and jasmonic acid (JA) signaling pathways using qRT-PCR, through which we discovered a unique preferential defense response of H. parviporum-infected Norway spruce under drought stress at the molecular level. Disturbances related to water availability, especially low water conditions can have negative effects on the tree host and benefit the infection ability of the pathogens in the host. From our RNA-seq analysis, 114 differentially expressed gene regions were identified between high (+) and low (−) water groups under pathogen attack. None of these gene pathways were identified to be differentially expressed from both non-treated and mock-control treatments between high (+) and low (−) water groups. Finally, only four genes were found to be associated with drought in all treatments.


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