Department of Agronomy, University of Missouri, 65211, Columbia, Missouri.
J Chem Ecol. 1992 Jul;18(7):1107-16. doi: 10.1007/BF00980066.
Tall fescue (Festuca arundinacea Schreb.) is a C-3 perennial grass noted for its persistence in harsh environments. Tall fescue persistence is enhanced byAcremonium coenophialum, a mutualistic fungal endophyte that increases resistance to drought, pathogens, and insects. This research was conducted to identify and elicit biochemical mechanism(s) that could account for tall fescue persistence. In initial studies, two cultivars known to differ in persistence were analyzed for chitinase, an antifungal hydrolase associated with disease resistance in other plants.Acremonium-infected Kentucky 31 (KY31), a persistent cultivar, and Johnstone, a nonpersistent cultivar, were inoculated with the parasitic nematode,Meloidogyne marylandi, grown for 50 days, and analyzed at 10-day intervals. Chitinase fluctuated throughout the 50-day period of seedling development, and activity was highest in the persistentAcremonium-infected KY31. In addition, chitinase was elicited by parasiticM. marylandi and expressed systemically. Subsequent studies were conducted to determine whether or not mutualisticAcremonium could increase chitinase activity. Genetically identical KY31, with and withoutAcremonium, were grown for 25 days and analyzed for chitinase at 5-day intervals. After 20 days,Acremonium-infected KY31 expressed more chitinase thanAcremonium-free KY31. We concluded that chitinase is related to tall fescue persistence; it was highest in the most persistent cultivar, increased under pathogen attack, and increased in the presence ofAcremonium, a symbiont known to enhance disease resistance.
高羊茅（Festuca arundinacea Schreb.）是一种 C-3 多年生禾本科植物，以在恶劣环境中的持久性而闻名。Acremonium coenophialum 是一种互惠共生的真菌内共生体，可提高高羊茅的抗旱性、抗病原体和抗虫性，从而增强高羊茅的持久性。本研究旨在确定和阐明可能导致高羊茅持久性的生化机制。在最初的研究中，分析了两个已知在持久性方面存在差异的品种的几丁质酶，几丁质酶是一种与其他植物抗病性相关的抗真菌水解酶。感染了 Acremonium 的肯塔基 31（KY31）和约翰斯顿，这两个品种均为持久性品种，接种了寄生线虫，Meloidogyne marylandi，生长 50 天，每隔 10 天分析一次。几丁质酶在幼苗发育的 50 天期间波动，在持久性的感染 Acremonium 的 KY31 中活性最高。此外，几丁质酶还被寄生的 M. marylandi 诱导并系统表达。随后的研究旨在确定互惠共生的 Acremonium 是否可以增加几丁质酶的活性。种植了具有和不具有 Acremonium 的遗传上相同的 KY31，生长 25 天，每隔 5 天分析一次几丁质酶。20 天后，感染 Acremonium 的 KY31 表达的几丁质酶多于没有感染 Acremonium 的 KY31。我们得出结论，几丁质酶与高羊茅的持久性有关；它在最持久的品种中最高，在受到病原体攻击时增加，并且在已知可增强抗病性的共生菌 Acremonium 存在时增加。
