Effect of Phenolic Structures on the Degradability of Cell Walls Isolated from Newly Extended Apical Internode of Tall Fescue (Festuca arundinacea Schreb.)
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- 作者：Marie André ; e Bernard Vailhé ; Gordon J. Provan ; Lorraine Scobbie ; Andrew Chesson ; Marie Paule Maillot ; Agnè ; s Cornu ; and Jean Michel Besle
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2000
- 出版时间：March 2000
- 年：2000
- 卷：48
- 期：3
- 页码：618 - 623
- 全文大小：59K
- 年卷期：v.48,no.3(March 2000)
- ISSN：1520-5118
文摘
Apical internodes of tall fescue (Festuca arundinacea Schreb. var. Clarine) harvested at floweringwere sectioned into 5 or 10 equal parts to study in situ degradability and cell wall composition,respectively. The basal (youngest) section had the greatest primary wall content. Cell walls in theupper (older) sections had the highest xylose/arabinose ratio and lignin content and a lignin rich insyringyl units, all typical of extensive secondary wall development. Almost all of the p-coumaric(p-CA) and about half of the ferulic acid (FA) were released by 1 M NaOH and presumed to beester-linked. The total FA content was approximately double that of p-CA in all sections other thanthe youngest with a distribution similar to that of total p-CA. However, the ratio of esterified toether and ether plus ester linked (Et & Et+Es) FA differed with age. Whereas the esterified formremained essentially constant (~4.5 g/kg of cell wall), Et & Et+Es ferulate increased with increasingage of the tissue and was significantly related to lignin deposition (r = 0.79, P < 0.01). The extentof cell wall degradation after 48 h of incubation in the rumen was inversely related to maturity,falling from 835 g/kg of dry matter in the youngest section to 396 g/kg in the oldest. Both the rateand extent of cell wall degradation were significantly negatively related to the ratio of xylose toarabinose, lignin content, proportion of syringyl units present in lignin, and concentration of Et &Et+Es FA present. A positive relationship between Et & Et+Es FA was also found, with the rate(P < 0.01) being better correlated than the extent (P < 0.05) of cell wall degradation. Applicationof the newly extended internode model to fescue produced results consistent with the view thatboth the lignin content and the extent to which lignin was covalently bound to the other wall polymerscrucially influenced the rate and extent of degradation.Keywords: Tall fescue; cell wall; lignin; phenolic acids; rumen degradability