Celorio-Mancera Maria de la Paz, Carl Greve L, Teuber Larry R, Labavitch John M
Plant Sciences, University of California, Davis, CA 95616, USA.
Arch Insect Biochem Physiol. 2009 Feb;70(2):122-35. doi: 10.1002/arch.20282.
Polygalacturonase (PG) activity found in the salivary gland apparatus of the western tarnished plant bug (WTPB, Lygus hesperus Knight) has been thought to be the main chemical cause of the damage inflicted by this mirid when feeding on its plant hosts. Early viscosity and thermal stability studies of the PG activity in L. hesperus protein extracts were difficult to interpret. Thus, it has been suggested that one or more PG protein(s) with different hydrolytic modes of action are produced by this mirid. In order to understand the quantitative complexity of the WTPB salivary PG activity, PG purification from a protein extract from salivary glands excised from L. hesperus insects was performed using affinity and ion exchange chromatography. To elucidate the qualitative complexity of the purified PGs, the digestion products generated by the PGs were separated using high performance anion exchange chromatography with pulsed amperometric detection. At least five PG proteins were detected; these differing in terms of their glycosylation, mass-to-charge ratios, and/or molecular mass. The characterization of the products generated by these PGs showed that endo- and exo-acting PGs are produced by WTPB. Although none of the PGs was purified to homogeneity, the present work provides biochemical evidence of a multiplicity of PGs that degrade the pectin component of the plant tissue in different fashions. The implications of these findings affect the understanding of WTPB feeding damage and, potentially, help identify ways to control this important crop pest. Arch. Insect Biochem. Physiol. 2008. (c) 2008 Wiley-Liss, Inc.
在西部 tarnished 植物蝽（WTPB，Lygus hesperus Knight）唾液腺器官中发现的多聚半乳糖醛酸酶（PG）活性，被认为是这种盲蝽取食其植物寄主时造成损害的主要化学原因。早期对 L. hesperus 蛋白提取物中 PG 活性的粘度和热稳定性研究难以解释。因此，有人提出这种盲蝽会产生一种或多种具有不同水解作用模式的 PG 蛋白。为了了解 WTPB 唾液 PG 活性的数量复杂性，使用亲和色谱和离子交换色谱从 L. hesperus 昆虫切除的唾液腺蛋白提取物中纯化 PG。为了阐明纯化的 PG 的质量复杂性，使用高效阴离子交换色谱和脉冲安培检测分离 PG 产生的消化产物。至少检测到五种 PG 蛋白；这些蛋白在糖基化、质荷比和/或分子量方面存在差异。对这些 PG 产生的产物的表征表明，WTPB 产生内切和外切作用的 PG。尽管没有一种 PG 被纯化至同质，但目前的工作提供了多种 PG 的生化证据，这些 PG 以不同方式降解植物组织的果胶成分。这些发现的意义影响了对 WTPB 取食损害的理解，并有可能有助于确定控制这种重要作物害虫的方法。《昆虫生物化学与生理学档案》2008 年。（c）2008 年 Wiley-Liss，Inc.
