A Flexible Growth Function for Empirical Use

Richards, Fred

doi:10.1093/jxb/10.2.290

Cited by 3,462 publications

(2,157 citation statements)

References 5 publications

Supporting

Mentioning

1,913

Contrasting

Unclassified

150

Order By: Relevance

“…Amylose and amylopectin content were determined according to the Megazyme International Ireland 2006. The processes of starch accumulation in the grain were fitted by Richards' (1959) Gene expression and expression rate calculation Gene expression was performed using a reverse transcriptase polymerase chain reaction (RT-PCR). Total RNA from endosperm was isolated using Trizol reagent (TianGen No.…”

Section: Enzyme Isolation Assays and Starch Measurementmentioning

confidence: 99%

Starch accumulation, activities of key enzyme and gene expression in starch synthesis of wheat endosperm with different starch contents

ZiBu

et al. 2011

J Food Sci Technol

View full text Add to dashboard Cite

In order to investigate starch accumulation, and the enzymes activity changes and the expression levels of genes and their relationships among them at different developmental stages of wheat grain. We choose Annong9912 and E28 were used in the study. During starch accumulating rate and grain filling rate, and there were obvious genotype difference between Annong9912 and E28. Whether low or high starch content of starch content, the accumulation courses of amylopectin, amylose and total starch were well fitted to the logistic equation by relating starch contents against DAP. The simulation parameters revealed that the higher contents of amylopectin and amylose resulted from earlier initiating accumulation time and greater accumulation rate. And amylose, amylopectin and total starch accumulation rate of two wheat cultures were significantly and positively correlated with activities of SBE, SSS and GBSS, but amylose accumulation rate of E28 had no correlation with the activities of SBE. In addition, there were significant correlations among activities of SBE, SSS and GBSS in two wheat cultivars. We speculated that these enzymes proteins may have a coordinating action in starch biosynthesis within the amyloplast, operating as functional multiprotein complexes. And expression levels of enzyme genes demonstrated a single-peak curve, and 12-18 DAP reached their peaks and then began to drop, and all had high expression level in earlier stage of endosperm development, but in E28 were higher than in Annong9912. The GBSS-I transcripts on average were expressed over 60 times more than GBSS-II transcript in E28. SBE, SSS, DBE may control starch synthesis at the transcriptional level, and GBSS-I may control starch synthesis at the post transcriptional level. The expression level of DBE on average was lower than SS-1 and SBE-IIa genes, and similar to SS-III and SBE-IIb genes, but higher than GBSS-I and GBSS-II genes.

show abstract

Section: Enzyme Isolation Assays and Starch Measurementmentioning

confidence: 99%

Starch accumulation, activities of key enzyme and gene expression in starch synthesis of wheat endosperm with different starch contents

ZiBu

et al. 2011

J Food Sci Technol

View full text Add to dashboard Cite

show abstract

“…Putter, Yaron and Bielorai, 1966), some non-linear (e.g. Richards, 1959;Nelder, Austin, Bleasdale and Salter, 1960), and recently some have been advanced which are only expressible by computer simulation (e.g. Paltridge, 1970;de Wit and Brouwer, 1968).…”

Section: Discussionmentioning

confidence: 99%

Regression methods for studying genotype-environment interactions

Hardwick

Wood

1972

Heredity

View full text Add to dashboard Cite

“…Instead, a relationship between k P and a 2 b was formulated for which it was found that for total body protein a 2 b < 2/9, with equality at maximum PR. This is in contradiction to the difference a 2 b 5 1 for the logistic or the monomolecular, to a 2 b 5 1/3 for the von Bertalanffy (1960) curve on the basis of a surface and volume argument and to a 2 b -0 for the Gompertz, which can be derived from equation (1) for a 5 1 and b -1 Hence, the conclusion follows that an argument based on the quantification of PR efficiency with the incorporation of protein turnover renders all the best known members of the Richards (1959) family of curves inappropriate for protein growth description. It therefore seems worthwhile to investigate what sort of scaling of physiological processes can characterize a family of curves resulting in a 2 b 5 2/9 or a 2 b 5 (4/9)Y, with Y representing the power in the relationship between cell volume and total protein in different tissues (Roux, 2006).…”

Section: Introductionmentioning

confidence: 94%

“…Variation in body mass growth form has been investigated by Gaillard et al (1997) by fitting the Richards (1959) growth curve family from birth to adulthood to 69 species of eutherian mammals. They showed Table 5 The fitting of equation (7) to average protein retention and protein maturity (P/a) in four growth periods on data published by Quiniou et al (1996) that growth form differs significantly among eutherian mammals and concluded that 'the commonly used Gompertz model can no longer be considered as the general model for the description of mammalian growth.'…”

Section: Experimental Evidencementioning

confidence: 99%

A family of protein growth curves with extension to other chemical body components together with application to animal nutrition and improvement

Roux

2011

Animal

View full text Add to dashboard Cite

Theory that successfully explains the magnitude and range of estimates of protein retention (PR) efficiency from the cost of turnover of existing protein indicates that conventional curves for growth description are inappropriate for protein growth. A solution to this problem is found in the consideration that the rate-limiting steps for protein synthesis (PS) and breakdown are likely to be associated with the diffusion of metabolites in and between cells. The algebraic scaling of nuclear and cellular diffusion capacity with tissue or total body protein leads to a parameterization of the primal differential equation for PR (kg/day) based on two terms representing PS and breakdown, viz.where c is an arbitrary constant, Q is the proportion of nuclei active in cell growth or division in a tissue or the whole body, a is the limit mass for protein (P, kg) in a tissue or the whole body, the power X 1 Z represents the rate-limiting steps in protein breakdown and Y is the power of the relationship between cell volume and the amount of tissue protein. For the whole body, the contribution of the different tissues should be weighted in proportion to their PS rates with, on average, Y 5 1/2. The constant 4/9 arises from the scaling of the specific diffusion rate of DNA activator precursors from nuclear dimensions and from the relationship between nuclear and cell volume. Experimental evidence on protein breakdown rate as well as protein and body mass points of inflection indicates that the range of theoretically possible numerical values of the rate-limiting powers X 1 Z 5 ( i 1 3)/9 for i 5 1, 2, y ,12 seems adequate for the description of the range of observed whole body protein and body mass growth patterns for mammals. Q 5 1 represents maximal protein retention, and for 0 , Q , 1, experimental evidence exists in support of a theoretical relationship between Q and food ingestion. The conclusion follows that some knowledge of the protein limit mass (a) and of the point of inflection (related to X 1 Z) is the main requirement for the application of the theory for description and prediction in animal nutrition and breeding.

show abstract

A Flexible Growth Function for Empirical Use

Cited by 3,462 publications

References 5 publications

Starch accumulation, activities of key enzyme and gene expression in starch synthesis of wheat endosperm with different starch contents

Starch accumulation, activities of key enzyme and gene expression in starch synthesis of wheat endosperm with different starch contents

Regression methods for studying genotype-environment interactions

A family of protein growth curves with extension to other chemical body components together with application to animal nutrition and improvement

Contact Info

Product

Resources

About