Growth and maintenance respiration of leaflet, stipule, tendril, rachis, and petiole tissues that make up the compound leaf of pea (Pisum sativum)

1996 ◽  
Vol 74 (8) ◽  
pp. 1331-1337 ◽  
Author(s):  
Donald E. Collier ◽  
Bernard Grodzinski

Respiratory changes during development, as well as growth and maintenance coefficients, were measured in organs of a typical compound leaf at the seventh node position of a pea (Pisum sativum) plant. The leaf consists of both laminar (leaflets and stipules) and cylindrical organs (tendrils, rachis, and petiole). Young tissue of each organ had relatively high respiration rates that declined as the tissue expanded. The respiration rates of leaflet, stipule, and tendril tissue throughout maturation were significantly greater than those of the other organs. The growth respiration coefficients were not significantly different among laminar and cylindrical organs. Maintenance respiration, expressed on a total dry mass basis and on a carbohydrate-corrected dry mass basis, as well as in vitro photosynthetic rates, were significantly lower in petioles and rachises than in tendrils or the leaflets and stipules. No difference in maintenance respiration of organs was observed when rates were expressed on a protein basis. A linear relationship between mass-based respiration and organ protein concentration was observed, suggesting that the energy costs involved in protein turnover may account, in part, for the differences in maintenance respiration among the organs. Taken together, our data show that although the tendril is structurally similar to the rachis, petioles, and stem, which have a role in supporting the canopy of this climbing plant, the respiratory properties of tendrils are more like those of leaflets and stipules, thus parallelling the photosynthetic characteristics of these organs in the compound leaf. Keywords: development, leaflets, Pisum sativum, respiration, stipules, tendrils.

1992 ◽  
Vol 22 (11) ◽  
pp. 1717-1721 ◽  
Author(s):  
Stan D. Wullschleger ◽  
Richard J. Norby

Atmospheric CO2 enrichment reportedly reduces respiration of mature leaves in a number of woody and herbaceous perennials. It has yet to be determined, however, whether these reductions reflect changes in maintenance respiration alone or whether CO2 might affect growth respiration as well. This possibility was examined in white oak (Quercusalba L.) seedlings that had been planted directly into the ground within open-top chambers and exposed to ambient, ambient +150 μL•L−1, and ambient +300 μL•L−1 CO2 concentrations over a 3-year period. In the spring of 1992, respiration rates were measured repeatedly during leaf expansion, and the growth and maintenance coefficients were determined using a two-component model. Specific respiration rates (mg CO2•g−1•h−1) were consistently lower for leaves of CO2-enriched saplings than for leaves of ambient-grown saplings. Partitioning these reductions in leaf respiration to either the growth or maintenance coefficients indicated a strong effect of CO2 on both components. The growth coefficient for leaves exposed to the ambient CO2 treatment was 964 mg CO2•g−1 compared with 849 and 664 mg CO2•g−1•for leaves from the two elevated CO2 concentrations, respectively. The maintenance coefficient was similarly reduced from a control rate of 114 mg CO2•g−1•d−1 to below 65 mg CO2•g−1•d−1 for leaves exposed to CO2 enrichment. Our results quantitatively describe the magnitude by which growth and maintenance respiration are affected by CO2 enrichment and as such should provide useful information for the future modeling of this phenomenon.


1986 ◽  
Vol 64 (6) ◽  
pp. 1268-1276 ◽  
Author(s):  
K. S. Gould ◽  
Elizabeth G. Cutter ◽  
J. P. W. Young

Leaf anatomy, ontogeny, and morphology were described and compared in a pea line (Pisum sativum L.) with conventional leaves and in isogenic lines carrying the mutations af (afila) or tl (tendril-less or acacia). The anatomy of stem, petiole, and rachis is not modified by these mutations. The tendrils, which in af replace leaflets, have normal tendril anatomy, and the terminal leaflets of the tl form have normal leaflet anatomy. The shoot apical dome has the same size and shape in the three genotypes, as does the leaf primordium up to the stage of initiation of the first laterals. The mature morphology of leaves varies with node of insertion. Some leaves, especially at nodes 3 and 4, have structures that are not typical of their genotype. An in vitro culture system is described for axillary shoots. Such shoots recapitulate most of the foliar features of seedling plants, but leaf morphology is on average more complex, and aberrant structures are more frequent. All these observations are discussed in relation to Young's algebraic model for compound leaf development.


Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1635
Author(s):  
Sweeny Chauhan ◽  
Alish Kerr ◽  
Brian Keogh ◽  
Stephanie Nolan ◽  
Rory Casey ◽  
...  

The prevalence of prediabetes is rapidly increasing, and this can lead to an increased risk for individuals to develop type 2 diabetes and associated diseases. Therefore, it is necessary to develop nutritional strategies to maintain healthy glucose levels and prevent glucose metabolism dysregulation in the general population. Functional ingredients offer great potential for the prevention of various health conditions, including blood glucose regulation, in a cost-effective manner. Using an artificial intelligence (AI) approach, a functional ingredient, NRT_N0G5IJ, was predicted and produced from Pisum sativum (pea) protein by hydrolysis and then validated. Treatment of human skeletal muscle cells with NRT_N0G5IJ significantly increased glucose uptake, indicating efficacy of this ingredient in vitro. When db/db diabetic mice were treated with NRT_N0G5IJ, we observed a significant reduction in glycated haemoglobin (HbA1c) levels and a concomitant benefit on fasting glucose. A pilot double-blinded, placebo controlled human trial in a population of healthy individuals with elevated HbA1c (5.6% to 6.4%) showed that HbA1c percentage was significantly reduced when NRT_N0G5IJ was supplemented in the diet over a 12-week period. Here, we provide evidence of an AI approach to discovery and demonstrate that a functional ingredient identified using this technology could be used as a supplement to maintain healthy glucose regulation.


1997 ◽  
Vol 75 (3) ◽  
pp. 492-500 ◽  
Author(s):  
Delphine Popiers ◽  
Frédéric Flandre ◽  
Brigitte S. Sangwan-Norreel

In vitro regeneration of pea (Pisum sativum L.), a regeneration recalcitrant legume, was optimised using thidiazuron. Buds were initiated from the meristems of the cotyledonary nodes of embryo axes, isolated from mature seeds, and subcultured on Murashige and Skoog medium supplemented with 13.3 μM 6-benzylaminopurine, 16.1 μM α-naphthaleneacetic acid, and 0.2 μM 2,3,5-triiodobenzoic acid. Proliferation of buds was preceded by the formation of white nodular-like protrusions. These structures were cut transversally in fine slices and subcultured on the same medium or in presence of thidiazuron that produces a second wave of secondary budding. The best results (90–110 buds per expiant) were obtained with 10 μM thidiazuron. The capacity of regeneration was genotype independent and reproducible. Buds elongated on the initial medium, then formed roots in presence of 5.37 μM α-naphthaleneacetic acid. and developed into viable plants. Key words: Pisum sativum L., regeneration, meristems, embryo axes, thidiazuron.


1995 ◽  
Vol 74 (5) ◽  
pp. 717-722 ◽  
Author(s):  
Erling S. Nordøy

Mammals are known to utilize wax esters with an efficiency of less than 50%. The purpose of the present study was to examine whether or not minke whales (Balaenoptera acutorostrata), which at times may eat considerable amounts of wax-ester-rich krill, represent an exception to this general pattern. Samples of fresh undigested forestomach, as well as colon, contents were obtained from minke whales (n5) that had been feeding on krill (Thysanoessa inermis) for some time. The samples were analysed for dry mass, energy density, lipid content and the major lipid classes, including wax esters. The concentrations of wax esters were compared with previous estimates of dry-matter disappearance of the same type of prey using anin vitrotechnique, to calculate the dry-matter digestibility of wax esters (DMDwax). Wax esters contributed 21% of the energy and 47% of total lipids in the krill diet. The energy density of gut contents decreased by 50% after their passage from forestomach to the end of the colon. The DMDwaxwas 94·1 (SD 2·8)% (n5). This high DMDwaxand the occurrence of fatty alcohols, one of the products of wax-ester hydrolysis, in faeces show that minke whales are very efficient digesters of wax esters and absorb most of the energy-rich products of this process.


2016 ◽  
Vol 68 (7-8) ◽  
pp. 762-770 ◽  
Author(s):  
Miaomiao Shi ◽  
Kai Wang ◽  
Shujuan Yu ◽  
Robert G. Gilbert ◽  
Qunyu Gao

2018 ◽  
Vol 8 (2) ◽  
pp. 389-395
Author(s):  
Luciane De Siqueira Mendes ◽  
Marcia Eugenia Amaral Carvalho ◽  
Willian Rodrigues Macedo ◽  
Paulo Roberto de Camargo e Castro

The use of plant growth regulators is directly related to the success of in vitro propagation, which is an advantageous alternative to obtain seedlings on a commercial scale. This study aimed to evaluate the in vitro development of ‘IAC 95-5000’ sugarcane seedlings after the addition of different doses of ethephon (0, 25, 50, 100 and 200 mg L-1) or gibberellic acid (0, 2.5, 5.0, 7.5 and 10.0 mg L-1) to the culture medium. Ethephon increased the number of tillers (up to 231.70%), reduced height of the main tiller (44.66 to 60.47%), and did not affect the shoot´s fresh and dry mass. On the other hand, gibberellin decreased the number of tillers and negatively changed biomass partitioning. It is concluded that the use of ethephon is a potential strategy to enhance in vitro production of ‘IAC 95-5000’ sugarcane seedlings, since it increased the number of usable shoots in subsequent subcultures, and its effects on height reduction can be reversible. However, the use of the tested doses of gibberellic acid is not recommended, because it impaired seedling development of this sugarcane variety.


1995 ◽  
Vol 120 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Jimmy L. Tipton ◽  
Marcia White

The objective of this study was to compare the structure and efficacy in terms of retarding cuticular transpiration of leaf cuticles from eastern redbud (Cercis canadensis L.) and dull-leaf and glossy-leaf Mexican redbud [Cercis canadensis var. mexicana (Rose) M. Hopk.]. Leaves of Mexican redbud exhibited several xeromorphic characteristics compared to eastern redbud: a smaller, thicker leaf with thicker cuticles, more cuticular wax, a higher specific leaf mass, and greater hydrated water content on a leaf area basis. Mexican redbuds with a glossy leaf differed from those with a dull leaf only in a thicker adaxial cuticle lacking wax crystallite on the surface. Epicuticular wax crystallite were present on the abaxial surface of all leaves examined. Detached leaves of eastern redbud had a higher water loss rate than those of Mexican redbud only on a dry mass basis, not on a leaf area basis. There was no difference in the rate of water loss by detached leaves of glossy-leaf and dull-leaf Mexican redbuds after 4 hours.


2013 ◽  
pp. 67-80
Author(s):  
Branislav Kovacevic ◽  
Dragana Miladinovic ◽  
Marina Katanic ◽  
Zoran Tomovic ◽  
Sasa Pekec

The effect of low initial medium pH on shoot and root development of five white poplar (Populus alba L.) genotypes was tested. The shoot height, fresh mass of shoots per jar, dry mass of shoots per jar, number of roots, as well as the length of the longest root were measured and final pH of the media determined, after 35 days of culture in vitro. Three initial pH values of the medium were tested: 3.0, 4.0 and 5.5 as control. Agar solidification at pH 3.0 was not achieved after sterilization in autoclave, but it was successful after sterilizing in a microwave oven. The obtained results indicate that the tested genotypes are able to significantly influence the changes of media pH during culture. The effect of differences among the examined media was significant for biomass accumulation and final media pH. Generally, significantly higher values of fresh and dry shoot mass, shoot height and the longest root length were recorded on a medium with initial pH 3.0 then on a standard medium with pH 5.5.The implications of the obtained results for the improvement of in vitro propagation of white poplars are discussed.


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