Differences in endosperm cell wall integrity in wheat (Triticum aestivum L.) milling fractions impact on the way starch responds to gelatinization and pasting treatments and its subsequent enzymatic in vitro digestibility

2019 ◽  
Vol 10 (8) ◽  
pp. 4674-4684 ◽  
Author(s):  
Konstantinos Korompokis ◽  
Niels De Brier ◽  
Jan A. Delcour

Intact wheat endosperm cell walls reduce intracellular starch swelling and retard its in vitro digestion by acting as physical barriers to amylolytic enzymes.

2016 ◽  
Vol 7 (10) ◽  
pp. 4202-4212 ◽  
Author(s):  
Jovyn K. T. Frost ◽  
Bernadine M. Flanagan ◽  
David A. Brummell ◽  
Erin M. O'Donoghue ◽  
Suman Mishra ◽  
...  

Higher amount of 4 M KOH-soluble cell wall pectic galactan is associated with lowerin vitrodigestibility in three New Zealand potato lines.


1974 ◽  
Vol 16 (3) ◽  
pp. 697-700 ◽  
Author(s):  
Iris L. Craig

Nine haploids (2n = 21) of Triticum aestivum L. (cv. Pitic–62) were obtained by in vitro anther culture, utilizing the medium described by Ouyang et al. (1973).


1974 ◽  
Vol 140 (1) ◽  
pp. 47-55 ◽  
Author(s):  
David Jones ◽  
Alex. H. Gordon ◽  
John S. D. Bacon

1. Two fungi, Coniothyrium minitans Campbell and Trichoderma viride Pers. ex Fr., were grown on autoclaved crushed sclerotia of the species Sclerotinia sclerotiorum, which they parasitize. 2. in vitro the crude culture filtrates would lyse walls isolated from hyphal cells or the inner pseudoparenchymatous cells of the sclerotia, in which a branched β-(1→3)-β-(1→6)-glucan, sclerotan, is a major constituent. 3. Chromatographic fractionation of the enzymes in each culture filtrate revealed the presence of several laminarinases, the most active being an exo-β-(1→3)-glucanase, known from previous studies to attack sclerotan. Acting alone this brought about a limited degradation of the glucan, but the addition of fractions containing an endo-β-(1→3)-glucanase led to almost complete breakdown. A similar synergism between the two enzymes was found in their lytic action on cell walls. 4. When acting alone the endo-β-(1→3)-glucanase had a restricted action, the products including a trisaccharide, tentatively identified as 62-β-glucosyl-laminaribiose. 5. These results are discussed in relation to the structure of the cell walls and of their glucan constituents.


1999 ◽  
Vol 19 (11) ◽  
pp. 7651-7660 ◽  
Author(s):  
Christopher P. Mattison ◽  
Scott S. Spencer ◽  
Kurt A. Kresge ◽  
Ji Lee ◽  
Irene M. Ota

ABSTRACT Mitogen-activated protein kinases (MAPKs) are inactivated by dual-specificity and protein tyrosine phosphatases (PTPs) in yeasts. InSaccharomyces cerevisiae, two PTPs, Ptp2 and Ptp3, inactivate the MAPKs, Hog1 and Fus3, with different specificities. To further examine the functions and substrate specificities of Ptp2 and Ptp3, we tested whether they could inactivate a third MAPK, Mpk1, in the cell wall integrity pathway. In vivo and in vitro evidence indicates that both PTPs inactivate Mpk1, but Ptp2 is the more effective negative regulator. Multicopy expression of PTP2, but not PTP3, suppressed growth defects due to the MEK kinase mutation, BCK1-20, and the MEK mutation,MKK1-386, that hyperactivate this pathway. In addition, deletion of PTP2, but not PTP3, exacerbated growth defects due to MKK1-386. Other evidence supported a role for Ptp3 in this pathway. Expression of MKK1-386 was lethal in the ptp2Δ ptp3Δ strain but not in either single PTP deletion strain. In addition, the ptp2Δ ptp3Δ strain showed higher levels of heat stress-induced Mpk1-phosphotyrosine than the wild-type strain or strains lacking either PTP. The PTPs also showed differences in vitro. Ptp2 was more efficient than Ptp3 at binding and dephosphorylating Mpk1. Another factor that may contribute to the greater effectiveness of Ptp2 is its subcellular localization. Ptp2 is predominantly nuclear whereas Ptp3 is cytoplasmic, suggesting that active Mpk1 is present in the nucleus. Last, PTP2 but not PTP3 transcript increased in response to heat shock in a Mpk1-dependent manner, suggesting that Ptp2 acts in a negative feedback loop to inactivate Mpk1.


2011 ◽  
Vol 59 (13) ◽  
pp. 7075-7082 ◽  
Author(s):  
Geraldine A. Toole ◽  
Gwénaëlle Le Gall ◽  
Ian J. Colquhoun ◽  
Phil Johnson ◽  
Zoltan Bedö ◽  
...  

2018 ◽  
Vol 22 ◽  
pp. 222-227
Author(s):  
O. M. Honcharuk ◽  
O. V. Dubrovna

Aim. Receiving of genetically modified plants of bread wheat with heterologous ornithine‑δ‑aminotransferase gene. Methods. Agrobacterium-mediated transformation of callus cultures in vitro, PCR-analysis. Results. By Agrobacterium-mediated transformation of the morphogenic calluses of bread wheat (Triticum aestivum L.) using the AGLO strain containing the binary vector pBi-OAT with the target ornithine-δ-aminotransferase (oat) and selective neomycinphosphotransferase II (nptII), transgenic plants-regenerators have been obtained. Conclusions. As a result of the genetic transformation of Zimoyarka variety, 12 wheat regenerants were obtained in the genome which revealed a complete integration of the genetic construct containing the oat and nptII transgenes. Keywords: Triticum aestivum L., Agrobacterium-mediated transformation, ornithine‑δ‑aminotransferase gene, PCR-analysis.


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