Pharmawati M, Shabala S N, Newman I A, Gehring C A
School of Biological and Chemical Sciences, Deakin University, Geelong, Victoria, Australia.
Mol Cell Biol Res Commun. 1999 Jul;2(1):53-7. doi: 10.1006/mcbr.1999.0151.
Recent evidence suggests that in plants, as in vertebrates, natriuretic peptides (NPs) regulate homeostasis. In this study noninvasive ion-selective vibrating microelectrodes were used to measure net fluxes of K+, Na+, and H+ in Zea mays root conductive tissue. Immunoreactant plant natriuretic peptides (irPNP) cause immediate net H+ influx and delayed net K+ and Na+ uptake. Delayed net K+ influx was also observed in response to 8-Br-cGMP, however, not accompanied by significant changes in net H+ fluxes. Furthermore, 8-Br-cGMP does not stimulate the plasma membrane H+-ATPase implying that cGMP directly affects cation channels. The data are consistent with NP and cGMP-dependent stimulation of nonselective cation channels with P(K) > P(Na) and point to a complex role for NPs in plant homeostasis.
最近的证据表明，在植物中，与脊椎动物一样，利钠肽（NP）调节体内平衡。在本研究中，使用非侵入性离子选择性振动微电极测量玉米根传导组织中K⁺、Na⁺和H⁺的净通量。免疫反应性植物利钠肽（irPNP）导致立即的净H⁺内流以及延迟的净K⁺和Na⁺摄取。响应8-溴-cGMP也观察到延迟的净K⁺内流，然而，净H⁺通量没有显著变化。此外，8-溴-cGMP不刺激质膜H⁺-ATP酶，这意味着cGMP直接影响阳离子通道。这些数据与NP和cGMP依赖的对P（K）>P（Na）的非选择性阳离子通道的刺激一致，并指出NP在植物体内平衡中具有复杂的作用。
