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为了进一步从离子动态运输方面了解沙枣(Elaeagnus angustifolia)耐盐机制和揭示沙枣种源间的K~+/Na~+平衡调控差异,该研究利用非损伤微测技术(non-invasive micro-test technology,NMT)测定银川种源(盐敏感型)和阿拉尔种源(耐盐型)沙枣幼苗根系在3种不同NaCl处理方式下的离子流:1)在150 mmol·L–1 NaCl胁迫24 h后的Na~+和K~+离子流;2)NaCl瞬时处理后的K~+和H~+的动态离子流;3)先NaCl胁迫24 h,再用Na~+/H~+逆向转运体抑制剂阿米洛利(Amiloride)和K~+通道抑制剂氯化四乙胺(TEA)处理后的Na~+和K~+离子流。结果表明:NaCl胁迫24 h后,沙枣根系Na~+和K~+外排净流量显著增加,并且银川种源沙枣幼苗根系Na~+净流量显著低于阿拉尔种源,净流量分别为720和912 pmol·cm~(–2)·s~(–1),而K~+外流净流量显著高于阿拉尔种源。瞬时NaCl处理后,沙枣根系K~+的外流迅速增加,并且银川种源的K~+外排净流量始终高于阿拉尔种源,而H~+由内流转为外排,阿拉尔种源的H~+净外流量大于银川种源。NaCl和NaCl+Amiloride处理下,阿拉尔种源沙枣幼苗Na~+外流的净流量均大于银川种源,但K~+外流的净流量均小于银川种源,而在对照和NaCl+TEA处理下,Na~+和K~+的净流量在两个种源间无明显差异。研究证明NaCl胁迫造成根系Na~+积累和K~+外流,沙枣幼苗为减少Na~+积累,通过根系Na~+/H~+逆向转运体将Na~+从体内排出,并且耐盐型种源沙枣幼苗根系在NaCl胁迫时能更好地维持体内的K~+/Na~+平衡,其原因主要在于具有较强的Na~+外排能力和较弱的K~+流失。该研究可以为进一步发掘优良耐盐沙枣种质资源提供理论参考依据。
In order to further understand the mechanism of salt tolerance in Elaeagnus angustifolia and reveal the balance of K ~ + / Na ~ + balance among different species of Elaeagnus angustifolia, this study utilized non-invasive micro- test technology, NMT) were used to determine the ion current of Yinzao seed (salt-sensitive) and Alar seed (salt-tolerant) roots under 3 different NaCl treatments: 1) Na + and K + ion currents after 24 h of stress; 2) dynamic ion currents of K + and H + after transient NaCl treatment; 3) + Reverse transporter inhibitor Amiloride and K + channel inhibitor tetraethylammonium chloride (TEA) treated Na ~ + and K ~ + ion current. The results showed that the net discharge of Na + and K + in the roots of A. jujuba cv. Ziziphus jujuba Mill. Increased significantly after 24 h of NaCl stress, and the net Na + flux was significantly lower than that of Aral sources Which was 720 and 912 pmol · cm -2 · s -1, while the net flux of K ~ + efflux was significantly higher than that of Alar origin. After the instantaneous NaCl treatment, the exudates of K + in the roots of Zanthoxylum bungeanum increased rapidly, and the net flux of K + efflux from Yinchuan provenances was always higher than that of Aral sources, while H + The source of H ~ + net outflow is greater than Yinchuan provenance. Under NaCl and NaCl + Amiloride treatments, the net fluxes of Na ~ + outflow from A. jujube seedling were higher than that of Yinchuan, but the net flux of K + outflow was less than that of Yinchuan. However, under the control and NaCl + TEA treatments , The net flux of Na ~ + and K ~ + showed no significant difference between the two provenances. Studies have shown that Na ~ + accumulation and K ~ + outflow are caused by NaCl stress. To reduce Na ~ + accumulation, Caragana microphylla seedling excreted Na ~ + from the body through Na ~ + / H ~ + antiporter and its salt tolerance The root of P. eureka L. seedlings could better maintain the balance of K ~ + / Na ~ + in NaCl solution under NaCl stress. The main reason is that it has stronger Na ~ + efflux ability and weaker K ~ + loss. This study can provide theoretical reference for further exploring the germplasm resources of excellent salt-tolerant jujube.