Call us toll-free

Biosynthesis and Genetic Regulation of Proanthocyanidins in

Biosynthesis and Genetic Regulation of Proanthocyanidins in Plants

Approximate price

Pages:

275 Words

$19,50

{Biosynthesis and genetic regulation of proanthocyanidins in ..

Brown cotton fiber is the major raw material for colored cotton industry. Previous studies have showed that the brown pigments in cotton fiber belong to proanthocyanidins (PAs). To clarify the details of PA biosynthesis pathway in brown cotton fiber, gene expression profiles in developing brown and white fibers were compared via digital gene expression profiling and qRT-PCR. Compared to white cotton fiber, all steps from phenylalanine to PA monomers (flavan-3-ols) were significantly up-regulated in brown fiber. Liquid chromatography mass spectrometry analyses showed that most of free flavan-3-ols in brown fiber were in 2, 3-trans form (gallocatechin and catechin), and the main units of polymeric PAs were trihydroxylated on B ring. Consistent with monomeric composition, the transcript levels of flavonoid 3′, 5′-hydroxylase and leucoanthocyanidin reductase in cotton fiber were much higher than their competing enzymes acting on the same substrates (dihydroflavonol 4-reductase and anthocyanidin synthase, respectively). Taken together, our data revealed a detailed PA biosynthesis pathway wholly activated in brown cotton fiber, and demonstrated that flavonoid 3′, 5′-hydroxylase and leucoanthocyanidin reductase represented the primary flow of PA biosynthesis in cotton fiber.

Biosynthesis and genetic engineering of proanthocyanidins and ..

Gene ontology (GO) analysis suggested that the cellular components of vehicles (including membrane-bounded vesicle and cytoplasmic vesicle) and membrane were most significantly over-represented in differentially expressed genes (DEGs) between white and brown fibers (). The most significantly over-represented Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in DEGs were oxidative phosphorylation and ubiquitin mediated proteolysis (). In addition, some DEGs were related to the physiological processes involved in regulation of fiber development, such as reactive oxygen and ethylene (). These data indicated that the brown fiber gene (Lc1) and/or pigment accumulation in cotton fiber may affect multiple aspects in fiber development other than fiber coloration.

"Biosynthesis and genetic regulation of proanthocyanidins in ..

and Genetic Regulation of Proanthocyanidins in ..

This book covers the biosynthesis and function of anthocyanins (and the related proanthocyanidins) in plants, and their applications in agriculture, food products, and human health. The book addresses wide-ranging issues that include human nutrition, the pastoral sector, cell culture production systems, food colorants, flower and fruit color, plant biotic interactions, and the responses of plants to environmental stress.

Kevin Davies leads the Plant Pigments Team of Crop & Food Research, Palmerston North, New Zealand. His group studies the molecular genetics of pigment biosynthesis in ornamentals, fruit and vegetables. A particular interest is the transcriptional regulation of flavonoid biosynthesis.

Biosynthesis and genetic regulation of proanthocyanidins in plants.

(2008) Biosynthesis and genetic regulation of proanthocyanidins in plants

In higher plants, PAs are synthesized through the flavonoid pathway from phenylalanine to flavan-3-ols () , , , . By DGE analysis of brown and white cotton fibers, a total of 34 PA synthase genes were identified (). Among these genes, 24 were significantly up-regulated in brown fiber, but none was significantly down-regulated. These up-regulated genes encoded 3 phenylalanine ammonia-lyases (PAL), 2 cinnamate 4-hydroxylases (C4H), 1 4-coumarate:CoA ligase (4CL), 6 chalcone synthases (CHS), 1 chalcone isomerase (CHI), 2 flavanone 3-hydroxylases (F3H), 2 flavonoid 3′, 5′-hydroxylases (F3′5′H), 2 dihydroflavonol 4-reductases (DFR), 2 leucoanthocyanidin reductases (LAR), 1 anthocyanidin synthase (ANS) and 2 anthocyanidin reductases (ANR). Thus, for every step from PAL to ANR in the PA biosynthesis pathway (), there was at least one encoding gene significantly up-regulated in brown fiber ().

To verify the result of DGE analysis, expression levels of the predominant PA synthase genes identified for all steps from phenylalanine to flavan-3-ols (, and ) and a flavonoid 3′-hydroxylase homologous gene (F3′H, Gorai.008G198200 from G. raimondii) were detected in brown and white fibers via qRT-PCR. Compared to white fiber, all of the 12 PA synthase genes were up-regulated in brown fiber (16∼260 fold, ). Furthermore, the high level expressions of PA synthase genes were co-segregated with brown fiber in individual RILs, as exemplified by LAR and F3′5′H genes (). These results were consistent with DGE profiles and confirmed that the brown fiber gene (Lc1) wholly activated PA biosynthesis pathway in cotton fiber.

Biosynthesis and genetic regulation of proanthocyanidins in ..
Order now
  • associated with the transcriptional up-regulation of the ..

    The transcription factor MYB115 contributes to the regulation of proanthocyanidin biosynthesis and enhances fungal ..

  • Biosynthesis and Genetic Regulation of ..

    R.A

  • Complex regulation of ABA biosynthesis in plants

    the transcriptional regulation of PA biosynthesis and the genetic manipulation of PAs.

Order now

Proanthocyanidin Biosynthesis in Plants

In attempt to clarify the details of PA biosynthesis pathway in brown cotton fiber, we performed a digital gene expression (DGE) analysis to compare the gene expression profiles in brown and white fibers. A total of 24 PA synthase genes were identified to be significantly up-regulated in brown fiber. Furthermore, we determined the chemical properties of PAs in brown fiber by using liquid chromatography-mass spectrometry (LC-MS) method. It was found that the majority of PA initiating units consisted of gallocatechin and the main extension units in brown fiber were trihydroxylated on B ring. These results demonstrated a detailed PA pathway involved in the brown pigmentation in cotton fiber, which may be essential to manipulate the biosynthesis of pigment and other flavonoids in cotton fiber.

Proanthocyanidin Biosynthesis in Plants ..

DGE analysis also revealed that transcript levels of different flavonoid synthases varied dramatically in cotton fibers ( and ). In white fiber, the synthases related to common steps in flavonoid biosynthesis (PAL, C4H, 4CL, CHS, CHI, F3H and F3′5′H) and PA specific steps (LAR and ANR) showed moderate expression levels (20∼200 TPM), while DFR and ANS had very low expression (). Although the whole PA pathway was significantly up-regulated in brown fiber, DFR and ANS had moderate (55.26 TPM) and low (7.34 TPM) expression levels, respectively, in comparison to much higher expression levels of other PA synthases (e.g. 940.2 TPM for F3′5′H and 616.43 TPM for LAR). These data suggested that the relative expression profile of different flavonoid synthase genes in cotton fiber was strictly regulated at transcription level.

Order now
  • Kim

    "I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."

  • Paul

    "Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."

  • Ellen

    "Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."

  • Joyce

    "Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."

  • Albert

    "Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."

  • Mary

    "Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."

Ready to tackle your homework?

Place an order