为探索不同类型耐盐植物在盐胁迫下体内渗透调节机制,以沙柳、沙枣、柽柳和西伯利亚白刺为研究材料,研究了不同盐浓度(0、100、200、300 mmol·L-1NaCl)处理下4种耐盐植物体内无机离子和有机溶质含量的变化,比较了其在植物渗透调节中的作用。结果表明:(1)盐处理后4种植物体内Na+、Cl-含量均上升,K+、Ca2+、Mg2+离子含量呈下降趋势;(2)稀盐型盐生植物白刺与泌盐型盐生植物柽柳以Na+为主要无机渗透调节物质,拒盐型耐盐植物沙枣与沙柳以K+为主要无机渗透调节物质;(3)可溶性糖是4种植物盐胁迫下共同的有机渗透调节物质,对沙柳和沙枣尤为重要;在高盐浓度(≥ 200 mmol·L-1NaCl)下,脯氨酸是沙枣叶片中重要的有机渗透调节剂;白刺叶片中甜菜碱含量随盐浓度升高明显增加,对提高白刺耐盐能力具有重要作用。4种不同类型耐盐植物在盐渍环境胁迫下所积累的渗透调节物质种类与数量差异明显,渗透调节方式与耐盐机制不同。

[Objective]To further understand the ion metabolism characteristics of Elaeagnus angustifolia L. under NaCl stress.[Method]The seedlings of two E. angustifolia L. provenances, which were Alaer (salt tolerance provenance) and Yinchuan (salt sensitive provenance), were treated by three NaCl concentrations (0,150,300 mmol·L-1) and sampled at the 7th day and the 30th day to measure the Na+ , K+, Ca2+, and Mg2+ contents, K+/Na+ ratio and selective absorption and transportation of K+ in tissues (roots, stems and leaves). [Result]The results showed that the Na+ content in the organizations of E. angustifolia L. sharply increased with the increase of NaCl concentration. With prolonging of stress time, the Na+ content increased in roots, and decreased in stems and leaves. After seedlings of the two provenances were treated with 150 mmol·L-1 NaCl for 7 days, the Na+ content was 2.10 times and 2.23 times in leaves, respectively, compared with the control groups, and was 1.79 times and 1.57 times in root. Meanwhile, the difference between two provenances showed a expanding trend with the increase of NaCl concentration and stress time. With the increase of NaCl concentration and extension of stress time, the K+ content, Ca2+ content and K+/Na+ ratio in organizations decreased gradually. Meanwhile, the Alaer provenance seedlings accumulated more Na+ in roots and less Na+ in leaves than that of Yinchuan provenance, and the K+ content, Ca2+ content and K+/Na+ ratio decreased less in the Alaer provenance seedlings than those of Yinchuan provenance. With the increase of NaCl concentration, the Mg2+ content in leaf gradually decrease, but the Mg2+ content in root increased 22.8~64.4% after salt stress for 7 days, and Alaer provenance seedlings increased more than Yinchuan provenance. After 30 days, there was non-significant difference with the control group on the Mg2+ content of root. K+ selective absorption of E. angustifolia L. seedlings significantly increased with increasing salt concentration of the media at the 7th days, whereas not obvious at the 30th days. When the concentration of NaCl in the media increased, the change of K+ selective transportation was not significant. [Conclusion]E. angustifolia L. seedlings increase Mg2+ content and K+ selective absorption in the roots at the early stage of salt stress to adapt saline environment. The salt-tolerance E. angustifolia L. provenance can cut off more Na+ in roots and reduce Na+ content in leaves, which cause less K+, Ca2+ and Mg2+ contents loss, especially the roots and leaves, so as to ensure that all kinds of metabolisms can go well.

目的 深入了解秋茄响应低温胁迫的分子机制以及培育秋茄的抗寒新品种。 方法 以耐寒红树植物‘龙港’秋茄1年生容器苗为实验材料，15 ℃处理12 h为对照组（CK），−5 ℃处理12 h为低温组（LT），采用 Illumina HiSeq测序平台进行转录组测序，挖掘脱落酸信号途径相关基因。 结果 转录组测序共鉴定到148个转录因子，分属于25个转录因子家族，其中，ERF、NAC、WRKY、bHLH、MYB、bZIP、HB-other和MYB-related等家族所包含的基因数量较多，分别为17、14、12、12、10、9、6和6；差异组共筛选到1 330个差异表达基因（Differentially Expressed Genes, DEGs），其中，698（52.48%）个上调表达，632（47.52%）个下调表达; KEGG通路富集分析发现，DEGs显著富集在植物激素信号转导、苯丙素生物合成、半乳糖代谢、光合作用-天线蛋白和α-亚麻酸代谢等通路中; 脱落酸信号途径相关基因 KoPYL1、KoABF1和KoABF2上调表达，KoPP2C1和 KoABF3下调表达，且这些基因表达情况与qRT-PCR验证结果一致。 结论 ERF、NAC、WRKY、bHLH、MYB、bZIP、HB-other和MYB-related等家族转录因子对秋茄响应低温胁迫起重要调控作用。植物激素信号转导、苯丙素生物合成、半乳糖代谢、光合作用-天线蛋白和α-亚麻酸代谢等是秋茄响应低温胁迫的重要KEGG通路。脱落酸信号途径中的KoPYL1、KoPP2C1、KoABF1、KoABF2和KoABF3基因可作为后期研究秋茄响应低温胁迫的重要候选基因。

采用盆栽的方法,对16种2年生幼苗盐(NaCl)胁迫40 d,并进行耐盐性研究。结果表明:随盐浓度的升高,各树种的脯氨酸、可溶性糖和甜菜碱含量均呈上升趋势,在400 mmol·L-1盐浓度下,沙枣和水蜡的脯氨酸含量比对照分别增加了662.0%和562.8%,而可溶性蛋白含量在各树种间差异较大;Na+和Cl-含量在不同部位(根、茎和叶)均随盐浓度增加而增加,鞑靼忍冬、药鼠李、风箱树和醉鱼草叶片中Na+含量增加了5~20倍。K+和Ca2+含量随树种不同表现各异。综合各树种盐害症状和渗透调节物质变化特性,认为柽柳、唐古特白刺、西伯利亚白刺、卫矛和沙柳具有高度耐盐性,水蜡、沙枣、糖朴、美国皂荚和药鼠李具有中高度耐盐性,杜梨、竹柳、鞑靼忍冬、醉鱼草、风箱树和美国白蜡具有中度耐盐性。脯氨酸、可溶性糖和矿质元素含量(尤其是Na+、K+和Cl-)的变化对植物耐盐能力的影响较普遍也较大。