Amino-acids in nutrition and growth. 1914.

Osborne, Thomas B.; Mendel, Lafayette B.

doi:10.1080/07315724.1993.10718340

Cited by 23 publications

(26 citation statements)

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“…The embryo of each individual was saved to extract genomic DNA for genotyping (Materials and Methods). PCR results showed that kernels 4,5,7,8,10,11,13,17,18,19,21,23,24, and 25 inherited the γRNAi gene (14 of 26 kernels) (Materials and Methods). As expected, the phenotypes of the zein accumulation patterns exhibited Mendelian segregation.…”

Section: Resultsmentioning

confidence: 99%

“…Kernels 1, 3, 12, 15, 22, and 26 were genotype Mo2/+; o2/o2, with the 27-kDa γ-zein increased, and α-zeins (22-and 19-kDa) and β-zein decreased. Kernels 8,10,11,13,17,18,19, and 21 were selected to represent the genotype Mo2/+; o2/o2; γRNAi/+, and showed similar phenotype to Mo2/+; o2/o2, except the knock-down of the 27-and 16-kDa γ-zeins. Kernels 4, 5, 7, 23, 24, and 25 were of Mo2/+; o2/o2; γRNAi/+ genotype, and showed decreased protein accumulation not only for α-and β-zeins, but also for the 27-and 16-kDa γ-zeins.…”

Section: Resultsmentioning

confidence: 99%

“…Because zeins are essentially devoid of lysine and tryptophan, their high-level accumulation results in poor grain-protein quality (17,18). The opaque2 (o2) mutant, identified by Singleton and Jones in the 1920s (19), initially showed great promise in monogastic animal feeding trials because it was shown to have twice the normal levels of lysine and tryptophan (15).…”

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γ-Zeins are essential for endosperm modification in quality protein maize

Holding

Messing

2010

Proc. Natl. Acad. Sci. U.S.A.

131

117

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Essential amino acids like lysine and tryptophan are deficient in corn meal because of the abundance of zein storage proteins that lack these amino acids. A natural mutant, opaque 2 (o2) causes reduction of zeins, an increase of nonzein proteins, and as a consequence, a doubling of lysine levels. However, o2's soft inferior kernels precluded its commercial use. Breeders subsequently overcame kernel softness, selecting several quantitative loci (QTLs), called o2 modifiers, without losing the high-lysine trait. These maize lines are known as "quality protein maize" (QPM). One of the QTLs is linked to the 27-kDa γ-zein locus on chromosome 7S. Moreover, QPM lines have 2-to 3-fold higher levels of the 27-kDa γ-zein, but the physiological significance of this increase is not known. Because the 27-and 16-kDa γ-zein genes are highly conserved in DNA sequence, we introduced a dominant RNAi transgene into a QPM line (CM105Mo2) to eliminate expression of them both. Elimination of γ-zeins disrupts endosperm modification by o2 modifiers, indicating their hypostatic action to γ-zeins. Abnormalities in protein body structure and their interaction with starch granules in the F1 with Mo2/+; o2/o2; γRNAi/+ genotype suggests that γ-zeins are essential for restoring protein body density and starch grain interaction in QPM. To eliminate pleiotropic effects caused by o2, the 22-kDa α-zein, γ-zein, and β-zein RNAis were stacked, resulting in protein bodies forming as honeycomb-like structures. We are unique in presenting clear demonstration that γ-zeins play a mechanistic role in QPM, providing a previously unexplored rationale for molecular breeding.electron microscopy | stacking of RNAi events | storage organs | opaque phenotype | kernel hardness G rain hardness is a key agronomic trait in maize (Zea mays L.)because it provides resistance to damage during harvesting and marketing, as well as to insect and fungal damage. Kernel texture is determined by the relative amounts of hard (vitreous) and soft (opaque) endosperm and there is a positive correlation between zein storage proteins and kernel vitreousness (1). Zeins are a heterogeneous mixture of alcohol-soluble proteins, falling into four classes based on their structure (α-, β-, γ-, and δ-zeins) (2). The zeins extracted with the Osborne method (3) are classified as z1 (19-and 22-kDa α-zeins) and the cross-linked z2 group (50-, 27-, and 16-kDa γ-zeins, 15-kDa β-zein, and 18-and 10-kDa δ-zeins) (4, 5). Zeins are deposited in rough endoplasmic reticulum-delimited protein bodies (PBs) in endosperm cells from around 10 d after pollination (DAP) (6, 7). Alpha-and δ-zeins are mainly stored in the center of PBs, and γ-and β-zeins are deposited in the peripheral region (8). The Cys-rich γ-and β-zeins have redundant function in the stabilization of PB morphology (9). The translucency (vitreousness) of the mature kernel is influenced by PB composition and the spatial organization of α-, β-, γ-, and δ-zeins (10-16).Because zeins are essentially devoid of lysine and tryptophan, their high-lev...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

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γ-Zeins are essential for endosperm modification in quality protein maize

Holding

Messing

2010

Proc. Natl. Acad. Sci. U.S.A.

131

117

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“…The awareness of AA balance had been originated by two leading investigators, Osborne and Mendel (1914). The word "amino acid imbalance" was initially used by Hier et al (1944) who found impaired growth of rats fed on diet having higher levels of AA such as glycine, phenylalanine, and proline than the required levels.…”

Section: Ideal Protein Ratiomentioning

confidence: 99%

Digestible Amino Acids: Significance and Prospects in Poultry

Ullah¹,

Ali²,

Mehr-un-Nisa³

et al. 2015

IJAB

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Amino acids (AA) are protein's hydrolytic products. In the recent years, poultry diets are being formulated on digestible AA (DAA) basis rather than total AA. Different techniques including precision-fed rooster assay, precision-fed cecectomized rooster assay, ileal AA digestibility and precision-fed broiler chick assay are used to determine the DAA coefficients of feed ingredients. However, nutritionists consider that the ileal digestibility in growing and adult birds is more accurate than other techniques. In all these digestibility techniques, apparent AA digestibility is corrected for endogenous AA losses to achieve standardized AA digestibility values. The digestibility values, determined using different digestibility techniques, of any feed ingredient vary. This variation in digestibility values can be minimized by adopting same digestibility technique for the estimation of DAA coefficients. Birds fed diets formulated on DAA basis resulted in better growth performance, feed efficiency and production economics. The main objective of this review is to examine the poultry's performance fed diet formulated based on the DAA.

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“…Because zeins are devoid of the essential amino acids lysine and tryptophan, their abundance results in poor-quality grain proteins (Osborne et al, 1914). In the 1960s, o2 was found to cause a reduction in zeins, a compensatory increase in non-zein proteins, and as a consequence, enhanced lysine levels (Mertz et al, 1964).…”

Section: Introductionmentioning

confidence: 99%

The Maize Imprinted Gene Floury3 Encodes a PLATZ Protein Required for tRNA and 5S rRNA Transcription through Interaction with RNA Polymerase III

Wang

et al. 2017

Plant Cell

118

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Maize (Zea mays) floury3 (fl3) is a classic semidominant negative mutant that exhibits severe defects in the endosperm but fl3 plants otherwise appear normal. We cloned the fl3 gene and determined that it encodes a PLATZ (plant AT-rich sequence and zinc binding) protein. The mutation in fl3 resulted in an Asn-to-His replacement in the conserved PLATZ domain, creating a dominant allele. Fl3 is specifically expressed in starchy endosperm cells and regulated by genomic imprinting, which leads to the suppressed expression of fl3 when transmitted through the male, perhaps as a consequence the semidominant behavior. Yeast two-hybrid screening and bimolecular luciferase complementation experiments revealed that FL3 interacts with the RNA polymerase III subunit 53 (RPC53) and transcription factor class C 1 (TFC1), two critical factors of the RNA polymerase III (RNAPIII) transcription complex. In the fl3 endosperm, the levels of many tRNAs and 5S rRNA that are transcribed by RNAPIII are significantly reduced, suggesting that the incorrectly folded fl3 protein may impair the function of RNAPIII. The transcriptome is dramatically altered in fl3 mutants, in which the downregulated genes are primarily enriched in pathways related to translation, ribosome, misfolded protein responses, and nutrient reservoir activity. Collectively, these changes may lead to defects in endosperm development and storage reserve filling in fl3 seeds.

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Amino-acids in nutrition and growth. 1914.

Cited by 23 publications

References 0 publications

γ-Zeins are essential for endosperm modification in quality protein maize

γ-Zeins are essential for endosperm modification in quality protein maize

Digestible Amino Acids: Significance and Prospects in Poultry

The Maize Imprinted Gene Floury3 Encodes a PLATZ Protein Required for tRNA and 5S rRNA Transcription through Interaction with RNA Polymerase III

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