Starch Granule Formation, Development of Starch Granules in Corn Endosperm

1957 ◽  
Vol 5 (3) ◽  
pp. 203-207 ◽  
Author(s):  
R. L. Whistler ◽  
W. L. Thornburg
1959 ◽  
Vol 12 (2) ◽  
pp. 146 ◽  
Author(s):  
LH May ◽  
MS Buttrose

Types, numbers, volumes, and weights of starch granules in the barley endosperm were measured at different times from anthesis to maturity. The formation of two types of granule was confirmed: the first (type A) was initiated until 15 days after anthesis; the second (type B) between 18 and 30 days. At maturity there were approximately 10 times as many type B granules as type A, although the latter made up 90 per cent. of the total granule volume. There was a linear relationship between starch granule and endosperm volume throughout kernel development, while the rate of increase in volume per unit granule volume was the same, irrespective of granule size, at anyone time. Starch weight increased as endosperm dry weight increased although the precise form of this relationship is in doubt. The interrelationships between starch granule weight and volume, and also endosperm dry weight and volume, suggest that both starch granules and endosperm increase in density during development.


2018 ◽  
Author(s):  
Camille Vandromme ◽  
Corentin Spriet ◽  
David Dauvillée ◽  
Adeline Courseaux ◽  
Jean-Luc Putaux ◽  
...  

AbstractThe initiation of starch granule formation is still poorly understood. However, soluble starch synthase 4 (SS4) appears to be a major component of this process since it is required to synthetize the correct number of starch granules in the chloroplasts of Arabidopsis thaliana plants. A yeast-2-hybrid screen allowed the identification of several putative SS4 interacting partners. We identified the product of At4g32190 locus as a chloroplast-targeted PROTEIN INVOLVED IN STARCH INITIATION (named PII1). Arabidopsis mutants devoid of PII1 display an alteration of starch initiation process and accumulate, on average, one starch granule per plastid instead of the 5 to 7 granules found in plastids of wild-type plants. These granules are larger than in wild type and they remain flat and lenticular. pii1 mutants display wild-type growth rates and accumulate standard starch amounts. Moreover, starch characteristics, such as amylopectin chain length distribution, remain unchanged. Our results reveal the involvement of PII1 in starch priming process in Arabidopsis leaves through interaction with SS4.


2021 ◽  
Vol 12 ◽  
Author(s):  
Kijong Song ◽  
Dae-Woo Lee ◽  
Jeongheon Kim ◽  
Jaewook Kim ◽  
Hwanuk Guim ◽  
...  

Starch granules in the endodermis of plant hypocotyls act as statoliths that promote hypocotyl negative gravitropism—the directional growth of hypocotyls against gravity—in the dark. To identify the molecular components that regulate hypocotyl negative gravitropism, we performed a mutagenesis screen and isolated reduced gravitropic 1 (rgv1) mutants that lack starch granules in their hypocotyl endodermis and show reduced hypocotyl negative gravitropism in the dark. Using whole genome sequencing, we identified three different rgv1 mutants that are allelic to the previously reported early starvation 1 mutant, which is rapidly depleted of starch just before the dawn. ESV1 orthologs are present in starch-producing green organisms, suggesting ESV1 is a functionally conserved protein necessary for the formation of starch granules. Consistent with this, we found that liverwort and rice ESV1 can complement the Arabidopsis ESV1 mutant phenotype for both starch granules and hypocotyl negative gravitropism. To further investigate the function of ESV1 in other plants, we isolated rice ESV1 mutants and found that they show reduced levels of starch in their leaves and loosely packed starch granules in their grains. Both Arabidopsis and rice ESV1 mutants also lack starch granules in root columella and show reduced root gravitropism. Together, these results indicate ESV1 is a functionally conserved protein that promotes gravitropic responses in plants via its role in starch granule formation.


2012 ◽  
Vol 550-553 ◽  
pp. 1513-1521
Author(s):  
Sirirat Thothong ◽  
Klanarong Sriroth ◽  
Rattana Tantatherdtam ◽  
Amnat Jarerat

To improve the miscibility of native rice starch granules and poly(butylene adipate-co-terephthalate)(PBAT), rice starch was hydrolyzed by a mixture of α-amylase and amyloglucosidase. The obtained porous rice granular starch was then mechanically blended with PBAT by single screw extruder. Many pits and holes on the surface of starch granules were observed by scanning electron microscopy (SEM). The rough surface of the rice starch granules improved the compatibility of the polymers in the blends, which consequently increased the tensile strength and the elongation at break. In addition, SEM also revealed that the porous granules were homogeneously distributed in the polymer matrix with no appearance of gaps.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5859
Author(s):  
Qingting Liu ◽  
Yuan Zhou ◽  
Joerg Fettke

Transitory starch plays a central role in the life cycle of plants. Many aspects of this important metabolism remain unknown; however, starch granules provide insight into this persistent metabolic process. Therefore, monitoring alterations in starch granules with high temporal resolution provides one significant avenue to improve understanding. Here, a previously established method that combines LCSM and safranin-O staining for in vivo imaging of transitory starch granules in leaves of Arabidopsis thaliana was employed to demonstrate, for the first time, the alterations in starch granule size and morphology that occur both throughout the day and during leaf aging. Several starch-related mutants were included, which revealed differences among the generated granules. In ptst2 and sex1-8, the starch granules in old leaves were much larger than those in young leaves; however, the typical flattened discoid morphology was maintained. In ss4 and dpe2/phs1/ss4, the morphology of starch granules in young leaves was altered, with a more rounded shape observed. With leaf development, the starch granules became spherical exclusively in dpe2/phs1/ss4. Thus, the presented data provide new insights to contribute to the understanding of starch granule morphogenesis.


2019 ◽  
Vol 71 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Tansy Chia ◽  
Marcella Chirico ◽  
Rob King ◽  
Ricardo Ramirez-Gonzalez ◽  
Benedetta Saccomanno ◽  
...  

Abstract In Triticeae endosperm (e.g. wheat and barley), starch granules have a bimodal size distribution (with A- and B-type granules) whereas in other grasses the endosperm contains starch granules with a unimodal size distribution. Here, we identify the gene, BGC1 (B-GRANULE CONTENT 1), responsible for B-type starch granule content in Aegilops and wheat. Orthologues of this gene are known to influence starch synthesis in diploids such as rice, Arabidopsis, and barley. However, using polyploid Triticeae species, we uncovered a more complex biological role for BGC1 in starch granule initiation: BGC1 represses the initiation of A-granules in early grain development but promotes the initiation of B-granules in mid grain development. We provide evidence that the influence of BGC1 on starch synthesis is dose dependent and show that three very different starch phenotypes are conditioned by the gene dose of BGC1 in polyploid wheat: normal bimodal starch granule morphology; A-granules with few or no B-granules; or polymorphous starch with few normal A- or B-granules. We conclude from this work that BGC1 participates in controlling B-type starch granule initiation in Triticeae endosperm and that its precise effect on granule size and number varies with gene dose and stage of development.


1992 ◽  
Vol 6 (2) ◽  
pp. 317-321 ◽  
Author(s):  
Rick A. Boydston

Experimental controlled release starch granules (CRSG) containing 5.3% a.i. (w/w) norflurazon or 6% a.i. (w/w) simazine retarded the leaching of both herbicides in loamy sand soil columns when compared to commercial formulations of norflurazon [80% (w/w) dry flowable] or simazine [90% (w/w) water dispersible granule]. Barley bioassays indicated norflurazon and simazine remained in the surface 0 to 2.5 cm of soil when applied as CRSG formulations and moved to a depth of 15 cm when applied as commercial dry formulations and leached with 6 cm of water. CRSG placed on pre-wetted soil columns began to release norflurazon by 7 d at 25 C or 14 d at 15 C, and subsequent leaching moved norflurazon beyond the top 2.5 cm of the soil column.


Animals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 626 ◽  
Author(s):  
NingNing Xu ◽  
DiMing Wang ◽  
JianXin Liu

The current study investigated differences of γ-zein protein contents and starch granule characteristics between raw and steam flaked corns and their influences on ruminal starch hydrolyzing bacteria (SHB) attached to corn grain. Two types of raw (Corn1 and Corn2) and their steam-flaked products (SFCorn1 and SFCorn2) were applied to explore physiochemical structures and SHB attachment. SDS-PAGE was conducted to detect γ-zein protein patterns, scanning electron microscope, and small angle X-ray scattering were performed to obtain starch granule morphology, while crystallinity, DQ starch, and DAPI staining were applied to quantify SHB. The steam flaking process destroyed γ-zein proteins and gelatinized starch granules. The median particle size of Corn1 and Corn2 starch granules increased from 17.8 and 18.0 μm to 30.8 and 26.0 μm, but crystallinity decreased from 22.0 and 25.0% to 9.9 and 16.9%, respectively. The percentage of SHB attached to Corn1 residues decreased (p = 0.01) after 4 h incubation, but SHB attached to SFCorn1 residues increased (p = 0.03) after 12 h incubation. Thus, the differences of γ-zein proteins and starch granule physiochemical structures between raw and steam flaked corn played an important role in improving the rate and extent of starch ruminal degradation through altering the process of SHB attached to corn.


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