Molecular Basis of Growth in Plants: Probing the Role of Wall Polysaccharides and Their Metabolism by Wall Proteins

植物细胞伸长是一种代谢变化的表现，它改变了壁内的承重键，使分子在内部压力的影响下发生位移。具体地说，该提议解决了这样的假设，即特定的壁多糖结构以这样一种方式被修饰，即这种承重键受到影响。所使用的检测系统将是玉米胚芽鞘。该提案探索的主要方向包括：1)开发一种体外系统来定量评估多糖与纤维素的结合。这个模型将允许确定结合受pH影响的程度以及酶改变结构后pH的影响。2)实验将扩大抗体是探索细胞壁新陈代谢的强大探针的观察。应用一系列葡聚糖和葡聚糖酶抗体得出的结果将扩大到确定组织暴露于葡醛酸阿拉伯木聚糖抗体的后果。阿魏酸的行为和与这些分子相连的二阿魏酸的作用将被评估。3)(2)的一个重要组成部分将是应用一种新的酶机制，使用葡萄糖醛酸木聚糖酶(以前称为铁黄原酶)来修饰葡萄糖醛酸阿拉伯木聚糖以确定结构(特别是葡萄糖醛酸组分和阿魏酸组分)。第二个强调的基础是观察到抗体的空间(定向)应用在其抑制生长的能力方面是重要的。这一努力将有助于确定表皮在控制伸长方面的作用。结构和代谢方面也将在分离的表皮细胞壁中进行检查。这项建议中描述的实验将有助于阐明植物生长的分子机制。

Plant cell elongation is an expression of metabolic changes that alter load bearing bonds within the wall to allow molecular displacement under the influence of internal pressures. Specifically, the proposal addresses the hypothesis that specific wall polysaccharide structures are modified in such a manner that such load bearing bonds are affected. The assay system utilized will be the Zea mays coleoptile. The major directions the proposal explores include: 1) The development of an in vitro system to quantitatively evaluate polysaccharide binding to cellulose. This model will allow a determination of the extent to which binding is affected by pH and the effect of pH after modification of structures by enzymes. 2) The experiments will extend the observation that antibodies are powerful probes to explore cell wall metabolism. The results derived from application of a family of glucan and glucanase antibodies will be extended to determine the consequences of exposure of tissue to glucuronoarabinoxylan antibodies. The behavior of ferulic acid and the role of diferulic acid linked to these molecules will be assessed. 3) An important component of (2) will be the application of a new enzyme mechanism, using glucuronoxylanase (previously called feraxanase), to modify glucuronoarabinoxylans to determine structure (especially glucuronic acid and ferulic acid components). A second emphasis is based on the observation that spatial (directional) application of antibodies is important in their capacity to suppress growth. This effort will help to determine the role of the epidermis in controlling elongation. Structural and metabolic aspects will also be examined in isolated epidermal cell walls. The experiments described in this proposal will help to elucidate the molecular mechanism of plant growth.//