Seasonal patterns of reserve and soluble carbohydrates in mature sugar maple (Acer saccharum)

2003 ◽  
Vol 81 (8) ◽  
pp. 780-788 ◽  
Author(s):  
B L Wong ◽  
K L Baggett ◽  
A H Rye

Sugar maple (Acer saccharum Marsh.) trees exhibit seasonal patterns of production, accumulation, and utilization of nonstructural carbohydrates that are closely correlated with phenological events and (or) physiological processes. The simultaneous seasonal patterns of both reserve and soluble carbohydrates in the leaves, twigs, branches, and trunks of healthy mature sugar maple trees were characterized. The concentrations of starch and soluble sugars ( sucrose, glucose, fructose, xylose, raffinose, and stachyose) were determined. Starch, the major reserve carbohydrate in sugar maple, is low during the active photosynthetic growth season. Starch is accumulated in the xylem ray tissues in late summer and early fall. During the cold season, there is a close relationship between starch hydrolysis–accumulation and temperature. Soluble sugars increase when starch concentrations decrease during the cold months, and these sugars may play a role in cold tolerance. Patterns of change in the stem tissues are similar to those in the root tissues but with slight differences in the timing.Key words: starch, sucrose, glucose, fructose, raffinose, stachyose.


Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 293-305 ◽  
Author(s):  
B. L. Wong ◽  
K. L. Baggett ◽  
A. H. Rye

This study examines the effects of summer drought on the composition and profiles of cold-season reserve and soluble carbohydrates in sugar maple ( Acer saccharum Marsh.) trees (50–100 years old or ∼200 years old) in which the crowns were nondamaged or damaged by the 1998 ice storm. The overall cold season reserve carbohydrate profiles in twig wood tissue of drought-stressed (DS) trees and non-drought-stressed (NDS) trees were generally similar, although differences were observed in the amount of reserve carbohydrates in DS and NDS trees. The cold-season level of starch stored in DS trees in early autumn in the wood tissue was about one-third to one-fifth that in NDS trees. The cold season sugar content in the DS trees was significantly greater than can be attributed to degradation of stored starch, only. The level of sucrose in DS trees remained high throughout the winter until termination of dormancy and dehardening. The concentrations of winter glucose and fructose in DS trees attained peak levels at the time of dormancy termination and declined during dehardening. The profiles of glucose and fructose in DS and damaged DS trees were generally different from that of sucrose throughout the leafless phase. In contrast, profiles of glucose and fructose in NDS trees closely paralleled that of sucrose. Elevated levels of sucrose, glucose, and fructose in DS sugar maple trees during the cold season may function as osmoregulators for freeze protection. Low sugar level or lack of increase in sugar level following dehardening in DS trees may suggest limited change in cellular constituents in adapting to low temperatures.



2005 ◽  
Vol 83 (6) ◽  
pp. 668-677 ◽  
Author(s):  
B L Wong ◽  
L J Staats ◽  
A S Burfeind ◽  
K L Baggett ◽  
A H Rye

To assess the effect of the ice storm of January 1998 on sugar maple (Acer saccharum Marsh.) tree health, starch, and soluble sugars in twigs from two damaged sugarbushes (younger: trees 50–100 years old, and older: trees approximately 200 years old) in northern New York were measured throughout the leafless phase (September 1998 – May 1999). Trees severely damaged by the ice storm exhibited signs of recovery during the first growth season (1998), that is, greater numbers of lateral (epicormic) shoots and increased wood production in the current year growth ring of branches at mid-crown, and high concentrations of starch in the twigs at the time of leaf drop. Differences in reserve and soluble sugar profiles between damaged and slightly damaged or undamaged sugar maple trees and between trees of the older sugarbush and those of the younger sugarbush indicate changes in cold season physiology of damaged trees in adapting to or tolerating cold temperature. In damaged trees of the younger and older sugarbushes, the profiles of sucrose, stachyose, raffinose, and xylose were similar to those of corresponding slightly damaged or undamaged trees throughout the cold season, except for late winter sucrose, glucose, and fructose profiles, which exhibited differences in concentration and profile configurations compared with respective slightly damaged or undamaged trees. A lower concentration of sucrose in damaged older tree wood tissue after dehardening in late winter and a lower concentration of "resynthesized" starch just prior to vernal growth were observed. The data indicate that the profiles of individual sugars can provide information on changes in physiological and biochemical processes in damaged trees during the cold season.Key words: starch, sucrose, glucose, fructose, raffinose, stachyose.



2002 ◽  
Vol 32 (4) ◽  
pp. 629-641 ◽  
Author(s):  
Philip M Wargo ◽  
Rakesh Minocha ◽  
Betty L Wong ◽  
Robert P Long ◽  
Stephen B Horsley ◽  
...  

A study established in 1985 in north-central Pennsylvania to determine effects of lime fertilization on declining sugar maple (Acer saccharum Marsh.) was evaluated in 1993 and showed that liming positively affected growth and crown vitality in sugar maple. This effect of lime on sugar maple offered an opportunity to assess other indicators of tree vitality and their response to lime additions. Foliar polyamines, starch and soluble sugars in root tissues, and cambial electrical resistance (CER) at breast height were evaluated. Foliar putrescine, soluble sugars, and CER decreased, while starch increased in lime-treated trees. Changes in these indicators were correlated with tree growth and crown vitality, which improved in limed plots. However, they were more highly correlated with lime-induced changes in foliar and soil elements and soil pH. Putrescine, soluble sugars, and CER decreased and starch increased, as Ca and Mg and molar ratios of Ca/Al and Mg/Mn increased and as Al and Mn decreased in both soil and foliage, and as soil pH increased. Results showed the beneficial effect of lime on tree vitality that was not reflected in visual assessments of crown vitality and demonstrated the potential utility of these physiological and biochemical measures as indicators of vitality in sugar maple.



2000 ◽  
Vol 132 (5) ◽  
pp. 681-684 ◽  
Author(s):  
P.J. Silk ◽  
G.C. Lonergan ◽  
D.C. Allen ◽  
J. Spear-O’Mara

Significant outbreaks of saddled prominent, Heterocampa guttivitta (Walker), have been recorded in northern hardwood stands throughout the northeastern United States since 1907 and were first noted in Ontario in 1938 (Martinat and Allen 1988). The insect overwinters as a pupa beneath litter, adult emergence begins in late May and peaks in mid-June, and oviposition activity ends in early July. Consequently, the major impact of defoliation usually occurs in late summer feeding. Principal hosts are sugar maple, Acer saccharum Marsh. (Aceraceae), American beech, Fagus grandifolia (Ehrh.) (Fagaceae), and yellow birch, Betula alleghaniensis Britton (Betulaceae) (Rush and Allen 1987). Two successive years of severe (>75%) defoliation of sugar maple result in significant growth loss (Bauce and Allen 1991), and heavy mortality may occur to understory sugar maple (Grimble and Newel1 1973). The quantity and sugar content of sugar maple sap are dramatically reduced the spring following heavy (>50%) defoliation (Magasi 1981; Handy 1968). Heavy to severe defoliation may cause crown dieback and defoliation and, in concert with other stresses, may initiate maple decline (Giese et al. 1964). Currently, monitoring and evaluation of saddled prominent populations must rely on egg sampling (Grimble and Kasile 1974), a time-consuming process that is inconvenient for survey personnel and landowners. A sex pheromone has not been identified for this species (nor for any other North American Notodontidae) and would be a potentially useful tool for detecting incipient outbreaks, predicting population levels, and evaluating population trends.



2020 ◽  
Vol 52 (3) ◽  
pp. 292-297
Author(s):  
Tara Lee Bal ◽  
Katherine Elizabeth Schneider ◽  
Dana L. Richter


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1333
Author(s):  
Jana Gregorova ◽  
Petra Vychytilova-Faltejskova ◽  
Sabina Sevcikova

MicroRNAs are small non-coding single-stranded RNA molecules regulating gene expression on a posttranscriptional level based on the seed sequence similarity. They are frequently clustered; thus, they are either simultaneously transcribed into a single polycistronic transcript or they may be transcribed independently. Importantly, microRNA families that contain the same seed region and thus target related signaling proteins, may be localized in one or more clusters, which are in a close relationship. MicroRNAs are involved in basic physiological processes, and their deregulation is associated with the origin of various pathologies, including solid tumors or hematologic malignancies. Recently, the interplay between the expression of microRNA clusters and families and epigenetic machinery was described, indicating aberrant DNA methylation or histone modifications as major mechanisms responsible for microRNA deregulation during cancerogenesis. In this review, the most studied microRNA clusters and families affected by hyper- or hypomethylation as well as by histone modifications are presented with the focus on particular mechanisms. Finally, the diagnostic and prognostic potential of microRNA clusters and families is discussed together with technologies currently used for epigenetic-based cancer therapies.



2017 ◽  
Vol 129 (2) ◽  
pp. 209-221 ◽  
Author(s):  
Amritpal S. Singh ◽  
A. Maxwell P. Jones ◽  
Mukund R. Shukla ◽  
Praveen K. Saxena




2015 ◽  
Vol 45 (6) ◽  
pp. 632-638 ◽  
Author(s):  
Kim Bannon ◽  
Sylvain Delagrange ◽  
Nicolas Bélanger ◽  
Christian Messier

Studies have reported divergent results on the effect of soil fertility and canopy opening on understory density and growth of sugar maple (AS; Acer saccharum Marsh.) and American beech (FG; Fagus grandifolia Ehrh.). The main objective of this study was to evaluate the effect of a gradient of canopy opening and soil fertility on the density and growth of AS and FG saplings in southwestern Quebec, Canada. We investigated 56 stands containing both AS and FG that were subjected to different disturbance history types (DHTs) (UF, unmanaged forest; PC, partial cut; and CC, clearcut) on various soil types. AS and FG absolute and relative sapling density varied greatly among the 56 stands; however, no significant effects of DHT, soil nutrient availability, or their interaction were found. Both species responded positively in terms of radial growth to canopy openings, with FG growth being slightly better than AS growth in PC stands compared with other canopy treatments. Contrary to our hypothesis, AS did not show significantly higher growth than FG following clear-cutting. These results do not support the idea that AS abundance and growth could be promoted by increasing the intensity of the canopy opening during harvest, at least on the generally acidic and base-poor soils that were investigated.



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