Geology Reports⌕ Search
Home/Archive/USGS

USGS · 1007695

Hydrogen, oxygen, and carbon isotope ratios of cellulose from submerged aquatic Crassulacean acid metabolism and non-Crassulacean acid metabolism plants

L. Sternberg·M. J. DeNiro·Jon E. Keeley
View original source ↗Export metadata ↓

Abstract

Isotope ratios of cellulose and cellulose nitrate from aquatic Crassulacean acid metabolism (CAM) and non-CAM plants were determined. Cellulose oxygen istope ratios for all plants that grew together were virtually identical, whereas large differences were observed for hydrogen isotope ratios of cellulose nitrate between CAM and non-CAM plants. Carbon isotope ratios of cellulose nitrate did not differentiate CAM from non-CAM plants.

Explore related subjects

Plant PhysiologyArticle

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

L. Sternberg, M. J. DeNiro, Jon E. Keeley. 1984-09-01. Hydrogen, oxygen, and carbon isotope ratios of cellulose from submerged aquatic Crassulacean acid metabolism and non-Crassulacean acid metabolism plants. https://doi.org/10.1104/pp.76.1.68

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS1999

Biochemical analysis of plant protection afforded by a nonpathogenic endophytic mutant of Colletotrichum magna

A nonpathogenic mutant of Colletotrichum magna (path-1) was previously shown to protect watermelon (Citrullus lanatus) and cucumber (Cucumis sativus) seedlings from anthracnose disease elicited by wild-type C. magna. Disease protection was observed in stems of path-1-colonized cucurbits but not in cotyledons, indicating that path-1 conferred tissue-specific and/or localized protection. Plant biochemical indicators of a localized and systemic (peroxidase, phenylalanine ammonia-lyase, lignin, and salicylic acid) 'plant-defense' response were investigated in anthracnose-resistant and -susceptible cultivars of cucurbit seedlings exposed to four treatments: (1) water (control), (2) path-1 conidia, (3) wild-type conidia, and (4) challenge conditions (inoculation into path-1 conidia for 48 h and then exposure to wild-type conidia). Collectively, these analyses indicated that disease protection in path-1 colonized plants was correlated with the ability of these plants to mount a defense response more rapidly and to equal or greater levels than plants exposed to wild-type C. magna alone. Watermelon plants colonized with path-1 were also protected against disease caused by Colletotrichum orbiculare and Fusarium oxysporum. A model based on the kinetics of plant-defense activation is presented to explain the mechanism of path-1-conferred disease protection.

Plant Physiology↗
USGS1984

Carbon assimilation characteristics of the aquatic CAM plant Isoetes howellii

The relationship between malic acid production and carbon assimilation was examined in the submerged aquatic Crassulacean acid metabolism (CAM) plant, Isoetes howellii Engelmann. Under natural conditions free-CO 2 level in the water was highest at 0600 hours and 14 CO 2 assimilation rates in I. howellii were also highest at this time. After 0900 hours there was a similar pattern in (a) rate of free-CO 2 depletion from the water, (b) reduction of carbon assimilation rates, and (c) rate of deacidification in leaves. Rates of daytime deacidification increased under CO 2 -free conditions and as irradiance intensity increased. Nighttime CO 2 uptake was estimated to contribute one-third to one-half of the total daily gross carbon assimilation. CO 2 uptake, however, accounted for only one-third to one-half of the overnight malic acid accumulation. Internal respiratory CO 2 may be a substrate for a large portion of overnight acid accumulation as leaves incubated overnight without CO 2 accumulated substantial levels of malic acid. Loss of CAM occurred in emergent leaf tips even though submerged bases continued CAM. Associated with loss of CAM in aerial leaves was an increase in total chlorophyll, a/b ratio, and carotenoids, and a decrease in leaf succulence. δ 13 C values of I. howellii were not clearly distinguishable from those for associated non-CAM submerged macrophytes.

Plant Physiology↗
USGS1982

Gas exchange characteristics of the submerged aquatic Crassulacean acid metabolism plant, Isoetes howellii

The submerged aquatic plant Isoetes howellii Engelmann possesses Crassulacean acid metabolism (CAM) comparable to that known from terrestrial CAM plants. Infrared gas analysis of submerged leaves showed Isoetes was capable of net CO 2 uptake in both light and dark. CO 2 uptake rates were a function of CO 2 levels in the medium. At 2,500 microliters CO 2 per liter (gas phase, equivalent to 1.79 milligrams per liter aqueous phase), Isoetes leaves showed continuous uptake in both the light and dark. At this CO 2 level, photosynthetic rates were light saturated at about 10% full sunlight and were about 3-fold greater than dark CO 2 uptake rates. In the dark, CO 2 uptake rates were also a function of length of time in the night period. Measurements of dark CO 2 uptake showed that, at both 2,500 and 500 microliters CO 2 per liter, rates declined during the night period. At the higher CO 2 level, dark CO 2 uptake rates at 0600 h were 75% less than at 1800 h. At 500 microliters CO 2 per liter, net CO 2 uptake in the dark at 1800 h was replaced by net CO 2 evolution in the dark at 0600 h. At both CO 2 levels, the overnight decline in net CO 2 uptake was marked by periodic bursts of accelerated CO 2 uptake. CO 2 uptake in the light was similar at 1% and 21% O 2 , and this held for leaves intact as well as leaves split longitudinally. Estimating the contribution of light versus dark CO 2 uptake to the total carbon gain is complicated by the diurnal flux in CO 2 availability under field conditions.

Plant Physiology↗