Gehring C A, Irving H R
Biotechnology Department, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa.
Int J Biochem Cell Biol. 2003 Sep;35(9):1318-22. doi: 10.1016/s1357-2725(03)00032-3.
Immunological and physiological evidence suggests the presence of biologically active natriuretic peptide hormones (NPs) in plants. Evidence includes specific binding of rat atrial NP, [rANP (99-126)] to plant membranes and the promotion of cyclic guanosine-3',5'-monophosphate (cGMP) mediated stomatal responses. Furthermore, anti-ANP affinity purifies biologically active plant immunoreactants (irPNPs) and a biologically active Arabidopsis thaliana irPNP (AtPNP-A) has been identified. AtPNP-A belongs to a novel class of molecules that share some similarity with the cell wall loosening expansins but do not contain the carbohydrate-binding wall anchor, thus suggesting that irPNPs and ANP are heterologues. We hypothesise that irPNP-like molecules have evolved from primitive glucanase-like molecules that have been recruited to become systemically mobile modulators of homeostasis acting via the plasma membrane. Such a function is compatible with localisation in the conductive tissue and the physiological and cellular modes of action of irPNPs reported to-date.
免疫学和生理学证据表明植物中存在具有生物活性的利钠肽激素（NP）。证据包括大鼠心房NP[rANP(99 - 126)]与植物膜的特异性结合以及环磷酸鸟苷（cGMP）介导的气孔反应的促进。此外，抗ANP亲和纯化具有生物活性的植物免疫反应物（irPNP），并且已鉴定出一种具有生物活性的拟南芥irPNP（AtPNP - A）。AtPNP - A属于一类新型分子，与细胞壁松弛扩展蛋白有一些相似之处，但不包含碳水化合物结合的壁锚，因此表明irPNP和ANP是异源物。我们假设irPNP样分子从原始的葡聚糖酶样分子进化而来，这些分子已被招募成为通过质膜起作用的内环境稳定的系统性移动调节剂。这样的功能与在传导组织中的定位以及迄今为止报道的irPNP的生理和细胞作用模式是相容的。
