Storage Protein Content Research Articles

Quantitative trait loci influencing grain protein content in tetraploid wheats

AbstractSeed storage protein content of durum wheat (Triticum turgidum var. durum) has an important effect on nutritional value and pasta‐making characteristics. The objective of this study was to determine by association with genetic markers the number, chromosomal location, and magnitude of effect of quantitative trait loci (QTLs) controlling protein concentration in kernels. A set of 65 recombinant inbred lines (RIs) was developed by single seed descent from a cross between cultivated durum wheat cv. ‘Messapia’ (low protein content) and accession MG4343 of the wild tetraploid wheat var. dicoccoides (high protein content). This population was characterized for eight morphological, six storage protein, one isozyme and 124 RFLP loci. Field trials were conducted in one location in 1993 and two locations in 1994. QTLs were mapped by regression analysis on each marker locus for each location and for the average across environments. A total of six putative QTLs were located on chromosome arms 4BS, SAL, 6AS, 6BS and 7BS. The number and size of QTLs detected varied across environments. The marker with the highest r2 value per QTL in each environment and across environments was chosen for a multiple linear regression analysis, which explained 49.2‐ 56.4% of the phenotypic variation for protein content. Only some of the markers were found to be negatively associated with plant grain yield and/or seed weight in one or two of the environments.

Fall acclimation patterns of interior spruce seedlings and their relationship to changes in vegetative storage proteins.

Changes in the content of vegetative storage proteins (VSPs) were monitored in 1-year-old interior spruce (Picea glauca (Moench) Voss x Picea engelmanni Parry complex) seedlings from late summer until midwinter. Seedlings were also monitored for days to terminal bud break (DBB(t)), dry weight fraction and frost hardiness, measured as both index of injury at -18 degrees C (IL(-18 degrees C)) and as the temperature causing 50% foliage electrolyte leakage (LT(50)). During fall acclimation, VSP content, frost hardiness and dry weight fraction increased, whereas DBB(t) decreased. In mid-November, IL(-18 degrees C) reached its lowest value, coinciding with high VSP content and dry weight fraction, and low DBB(t). The LT(50) decreased in a linear manner as dry weight fraction and VSP content increased; r(2) values were 0.69 to 0.81, respectively. The fall accumulation of VSPs was also highly correlated with increased dry weight fraction. The increase in VSP content occurred as seedling photosynthetic capacity declined, but maximum contents were obtained before complete inactivation of the photosynthetic apparatus. The results indicate that VSP accumulation is an integral part of fall acclimation in interior spruce, closely parallels frost hardiness and partially accounts for the increase in dry weight fraction.

Storage proteins in adult ants ( Camponotus festinatus): Roles in colony founding by queens and in larval rearing by workers

Camponotus festinatus storage hexamers (Hex 1 and 2), first identified in last instar larvae, constitute two major proteins in adult queens and broodless workers. We have examined the effects of colony founding by queens and larval rearing by workers on their storage protein content. Both hexamerins accumulate in virgin queens, particularly Hex 2 in the fat body where it makes up about 70% of total soluble proteins. Colony founding causes a depletion of Hex 1 and 2 in queens. Levels of these proteins begin to decrease by the end of the claustral period when the first workers emerge, and they are depleted from fat body and hemolymph 1 month later. Larval rearing has an inhibitory effect on the accumulation of storage proteins in workers. Hex 1 occurs only in low concentrations in the hemolymph of 2- and 4-week-old workers kept with larvae, and disappears thereafter. Hex 2 does not accumulate in 2- to 8-week-old workers kept with larvae. Our results with Camponotus queens support a role of the storage hexamers in egg development and/or nourishment of the brood. These data also suggest an important role of nutrition in the synthesis and accumulation of hexamerins in adult workers.

Clonal variation in apical growth and content in vegetative storage proteins in Populus

Apical shoot growth and storage protein content in various poplar species and clones were followed in trees growing in the field and in micropropagated plants cultivated in the growth chamber under a controlled environment. In autumn a 32 kD and a 36 kD vegetative storage protein accumulate in wood, bark and roots of poplar and comprise together about 25% of the soluble proteins. In spring, at the time of dormancy break, the storage proteins are degraded and 3 weeks after budburst these proteins are no longer immunologically detectable. As in autumn, short day exposure of black cottonwood plants (Populus trichocarpa Torr. and Gray) induces cessation of apical growth and accumulation of the 32 kD and 36 kD vegetative storage proteins in all clones studied. In order to simulate spring conditions, short day induced plants were transferred back to long days. Like the situation in spring, budburst and storage protein degradation occurred considerably earlier in clone 9/60 than in clone Muhle Larsen. The latter clone accumulates both in winter and after short day exposure more storage proteins than the former. Furthermore two P. trichocarpa clones differ qualitatively in storage protein content: they possess an additional 34 kD polypeptide which cross-reacts with the anti-32 kD antibody. In conclusion, apical shoot growth and the capacity to synthesize storage proteins can be easily followed in micropropagated poplar cultivated in the growth chamber under inducing photoperiods. This offers the major advantage of independence from the annual growth cycle. Within one species considerable clonal variance in storage protein content and in the induction times needed for dormancy and dormancy break were observed. The suitability of storage protein content and apical growth as early selection traits in breeding programs focusing on nitrogen efficient poplar and clones adapted to specific latitudes will be discussed.

Regulation of ammonium ion salvage and enhancement of the storage protein contents of corn, sweet potato, and yam tuber by N-(carboxymethyl)chitosan application

The biochemical approach to storage protein enhancement via NH 4 + ion metabolism was investigated by treatment of growing yam tuber, sweet potato, and corn with N-(carborymethyl)chitosan (NCMC). Application of NCMC to yam tuber gave rise to α-ketoglutarate (αKG)-dependent inhibition of the glutamate synthase (GOGAT) with an inhibition constant (K i ) of 3 mM but relieved the αKG-dependent inhibition of the glutamate dehydrogenase (GDH)

An analysis of seed development inPisum sativum V. Fluorescence triple staining for investigating cotyledon cell development

A triple staining technique has been developed to investigate the relationship between the increase in DNA content and initiation of storage protein synthesis in pea cotyledon cells. Cells were separated by incubation with macerozyme providing a population comparable to conventional chromic acid techniques but with the advantage of retained immunogenicity. The staining technique combined indirect immunofluorescence using specific antibodies against the storage protein, vicilin, and the cytoskeletal protein, tubulin, with the DNA stain, 4′6-diamidino-2-phenylindole. Using the enzymically separated cells, the staining method allowed the visualisation of vicilin deposits and microtubules and the quantification of DNA by image analysis in thesame cells. The distribution of cellular DNA contents and storage protein content increased with the size of embryo. In small embryos a proportion of mitotic cells were seen to have increased amounts of DNA, though no spindle abnormalities were seen. Storage protein could be detected by immunofluorescence in individual cells much earlier than reported by previous workers but never in mitotic cells. The sensitivity of the immunofluoresence technique for detecting storage protein was determined as 0.5 pg per cell by estimating the vicilin production in whole pea embryos using an enzyme immunoassay.

Storage protein accumulation patterns in somatic embryos of cotton (Gossypium hirsutum L.)

The storage protein content of somatic embryos of Gossypium hirsutum L. cv. Coker 201 was determined using extinction level, antigen/antibody association detection methods. Mature storage protein was first detected in early globular-stage somatic embryos at a total concentration of 0.36% of the embryo protein mass. Tulip-stage and mature somatic embryos were comprised of 3.0% and 1.3% mature storage protein, respectively. Maximum storage protein synthesis was found to occur during early globular- and early heart-stages. During this period of development, significant levels of protein precursors were found also to accumulate. The pattern of storage protein synthesis, processing and accumulation paralleled the pattern that has been reported for the zygotic system, although somatic embryos accumulate storage protein at much earlier stages and to a lesser degree. The possibility of using complex biochemical pathways to monitor embryogenic systems in vitro is discussed.

The effect of the r a and r b loci on the lipid content of the seed of Pisum sativum

The lipid content of seed from a set of isogenic lines for the R a : r a locus has been determined; the results show that this locus as well as affecting the starch, sugar and storage protein content and composition, also has a marked effect on the lipid content of the seed. Genotypes having different combinations of alleles at the r a and r b loci have also been examined; an r a r a r b r b , genotype had 5.57% purified total lipid in its seed - a more than 2-fold increase over that found in the round-seeded varieties (R a R a R b R b ) usually grown for the dry sed crop.

Ovarian development in autogenous and anautogenous Lucilia cuprina in relation to protein storage in the larval fat body

Females of Lucilia cuprina from field populations and from normally maintained laboratory cultures are anautogenous. Normal anautogenous females were compared with females from a laboratory selected autogenous strain especially as regards protein storage and ovarian protein content. The following differences were found: (1) autogenous females at emergence from the puparium contain about 1 mg (20%) more protein than anautogenous females of equal fresh weight, (2) about 70% of this additional protein is accounted for by increased protein content of the abdominal larval fat body, (3) the larval fat body of autogenous females has greater volume and greater protein content per unit volume than that of anautogenous females, (4) the greater volume of larval fat body in autogenous females is the result of increased cell size rather than cell number, (5) the protein content of the ovaries of mature non-protein-fed autogenous females is about 1 mg. That of non-protein-fed anautogenous females of similar age is negligible, (6) the larval fat body of non-protein-fed anautogenous females disappears more rapidly after emergence than does that of autogenous females.

Genetic regulation of storaage protein content in maize endosperm.

Sodium dodecylsulfate-polyacrylamide gel electrophoresis reveals that zein prepared from normal maize inbred (Zea mays L.) contains six separable components. Z1 and Z2 are the predominant species, with molecular weights of 21,800 and 19,000 daltons. Amino acid analysis of these two components shows that both are rich in glutamic acid, leucine, and proline, but low in lysine. Of the four minor bands, Z3, Z4, Z5, and Z6, the latter two exist only in trace amounts. A mutation at the opaque-2 locus severely suppresses the synthesis of Z1. The nonallelic mutant, opaque-7, strongly suppresses the synthesis of Z3 and Z4, while slightly reducing Z2. On the other hand, the floury-2 mutant appears to reduce the synthesis of these six proteins in the same relative proportion. In the double mutant combinations, opaque-2 apparently is epistatic to opaque-7 and floury-2 in the synthesis of zein components. The glutelin fraction shows a more complex banding pattern; however, qualitative differences are not apparent among the mutant lines examined.

Study on the period of acceptability of cooked rice

The study attempts to determine the period of acceptability of cooked rice (parboiled) of Pajam variety. Cooling studies on cooked rice showed the highest cooling rate in soaked water, and successively followed by refrigeration, under fan air and at room temperature (30±2°C). The moisture, protein, fat, ash and total carbohydrate contents (wb) were 9.68, 4.93, 0.36, 0.32 and 84.71 % respectively in raw rice; 12.37, 8.36, 0.40, 0.57 and 78.29 % respectively in parboiled rice and 65.99, 3.24, 0.15, 0.14 and 30.47 % respectively in cooked rice (parboiled). After 24 hours of storage moisture, protein, fat, ash and carbohydrate contents were 66.47%, 5.69%, 0.13%, 0.14% and 15.73% respectively in rice at room temperature; 69.12 %, 3.64 %, 0.13 %, 0.13 % and 26.98 % respectively in refrigerated rice and 64.38 %, 3.53 %, 0.15 %, 0.15% and 31.78 % respectively in frozen rice. The cooked rice stored at room temperature for 24 hours showed 4.2x104cfu/g, and the refrigerated and frozen rice showed no viable load while after another 24 hours of storage the refrigerated rice showed 6.9x105cfu/g and frozen rice showed no load. The sensory evaluation revealed the 'cooked rice' and 'refrigerated and reheated rice' were equally acceptable and ranked as 'like very much' in terms of colour, taste, texture and overall acceptability. To ensure the maximum hygienic quality and desirable taste the cooked rice (parboiled) might be kept for a maximum period of 20 hours at room temperature and 48 hours in a refrigerator and reheated by microwave oven for 1 minute before serving to the consumer. Keywords: Period; Acceptability; Cooked rice DOI: 10.3329/jbau.v6i2.4840 J. Bangladesh Agril. Univ. 6(2): 401-408, 2008