Nothofagus dombeyi (Mirb.) Blume and Nothofagus nitida (Phil.) Krasser are closely related evergreen trees native to south central Chile. Nothofagus dombeyi is a pioneer in habitats subject to high daytime irradiances and nighttime freezing temperatures and has a wider altitudinal and latitudinal distribution than N. nitida, which is restricted to more oceanic climates. We postulated that N. dombeyi has a greater cold-acclimation capacity, expressed as a greater capacity to maintain a functional photosynthetic apparatus at low temperatures, than N. nitida. Because cold-acclimation may be related to the accumulation of cryoprotective substances, we investigated relationships between ice nucleation temperature (IN), freezing temperature (FT), and the temperature causing injury to 50% of the leaf tissues (LT(50)) on the one hand, and concentrations of total soluble carbohydrates (TSC), starch and proline on the other hand. Observations were made throughout a seasonal cycle in adults and seedlings in the field and in seedlings in the laboratory under cold-acclimation inductive and non-inductive conditions. In adults, LT(50) values were lower in N. dombeyi than in N. nitida, suggesting that N. dombeyi is the more frost tolerant species. Adults of both species tolerated freezing in autumn and winter but not in spring and summer. In the fall and winter, seedlings of N. dombeyi had a much lower LT(50) than those of N. nitida. Nothofagus nitida seedlings, in autumn and winter, exhibited freezing avoidance mechanisms. Although elevated TSC and proline concentrations may contribute to freezing tolerance in adults of both species, an increase in proline concentration is unlikely to be the dominant frost tolerance response in adults because proline concentrations were higher in N. nitida than in N. dombeyi. In seedlings, however, there were large differences in proline accumulation between species that may account for the difference between them in freezing tolerance. Starch concentration in both species decreased during winter. Chlorophyll fluorescence indicated that maximal photochemical efficiency (F(v)/F(m)) remained at optimal values (~0.8) throughout the year. The effective photochemical efficiency of PSII (PhiPSII) and relative electron transport rates (ETR(r)) decreased in winter in both species. In seedlings, fluorescence parameters were more affected in winter in N. nitida than in N. dombeyi. We concluded that adults and seedlings of N. dombeyi are hardier than adults and seedlings of N. nitida, which is consistent with its wider latitudinal and altitudinal distribution.

糖不仅是植物细胞的碳源、能源和结构物质,也是一种信号分子,在植物生长发育及响应逆境胁迫中起重要作用。非生物逆境如高温、低温、干旱、盐渍和重金属胁迫是限制作物产量的主要胁迫因子,糖作为信号分子在植物响应这些胁迫因子中的确切机理,尚未清楚。基于植物中糖信号转导途径及其在植物耐逆性形成中作用的最新研究进展,归纳了植物中分别依赖己糖激酶（HXK）、G蛋白信号1调节子（RGS1）、糖酵解（EMP）和磷酸戊糖途径（PPP）的糖信号转导途径,讨论了糖信号在植物耐逆性包括耐热性、耐冷性、耐旱性、耐盐性和重金属胁迫耐性形成中的作用,最后展望了糖信号在植物生物学领域的研究方向。

Induction of heat shock proteins (HSPs) in response to heat stress (HS) is indispensable for conferring thermotolerance. Glc, a fundamental signaling and metabolic molecule, provides energy to stressed seedlings to combat stress. The recovery of stressed plants from detrimental HS in response to Glc is largely mediated by HSPs, but the mechanistic basis of this thermotolerance is not well defined. In this study, we show that Glc has a prominent role in providing thermotolerance. Glc-mediated thermotolerance involves HSP induction via the TARGET OF RAPAMYCIN (TOR)-E2Fa signaling module. Apart from HSPs, TOR-E2Fa also regulates the Arabidopsis () ortholog of human, named - (). Expression of :: in the shoot apical meristem (SAM) after HS coincides with TOR-E2Fa expression, substantiating a role for TOR-E2Fa-HLP1 in providing thermotolerance. We also demonstrate that Glc along with heat could induce proliferation activity in the SAM after HS recovery, which was arrested by the TOR inhibitor AZD-8055. Molecular and physiological studies suggest that HS-activated heat stress transcription factor A1s also positively regulate transcription, suggesting convergence of the Glc and HS signaling pathways. Loss of functional HLP1 causes HS hypersensitivity, whereas HLP1 overexpressors display increased thermotolerance. HLP1 binds to the promoters of Glc-regulated HS-responsive genes and promotes chromatin acetylation. In addition, Glc modifies the chromatin landscape at thermomemory-related loci by promoting H3K4 trimethylation (H3K4me3). Glc-primed accumulation of H3K4me3 at thermomemory-associated loci is mediated through HLP1. These findings reveal the novel function of Glc-regulated in mediating thermotolerance/thermomemory response.© 2019 American Society of Plant Biologists. All Rights Reserved.

采用高效液相色谱法测定台农6 号菠萝果实中糖分含量的方法。以90% 乙醇作为提取液，色谱柱为CHO-820(钙型)糖柱(300mm × 7.8mm)，柱温90℃，流动相为超纯水，流速0.5ml/min，进样体积10μl，用示差折光检测器检测菠萝果实中的糖分。本方法的相对标准偏差为0.59%～0.85%，相关系数在0.9998 以上，加标回收率为98.84%～100.6%。台农6 号菠萝果肉含糖量与成熟季节有关，夏季果(7 月成熟)和秋季果(9 月成熟)含蔗糖最高，其次为葡萄糖和果糖，冬季果葡萄糖含量最高、蔗糖含量最低。

介绍了目前在液相色谱荧光衍生法分析糖类物质中常用的几类荧光衍生试剂及相应的衍生方法,对近期糖类物质分离分析中的液相色谱荧光检测方法做了系统综述。引用文献60篇。

建立了一种以 β 吲哚乙酸为内标物,用高效液相色谱内标法直接分离和测定植物中游离糖的新方法。木糖、果糖、葡萄糖、蔗糖、麦芽糖、乳糖和棉子糖的分离在 18min内完成 ;检出限分别达到 1 8μg,2 3μg,2 7μg,1 8μg,3 5 μg,4 1μg和 4 3μg,线性范围为 5 μg/L～ 75 0 μg/L。研究了流动相中乙腈的浓度、pH值对分离 7种糖和 β 吲哚乙酸的影响。方法用于枣和苹果样品的测定并进行回收率试验,结果为木糖、果糖、葡萄糖、蔗糖的 5次测定的回收率分别为 97 4%～ 10 2 1%,97 3%～ 10 1 8%,98 7%～ 10 2 2 %,97 7%～ 10 2 5 %,。

采用乙二胺动态修饰硅胶柱分离、蒸发光散射检测器测定了转基因烟草提取液中的糖。 4种糖的峰面积标准曲线在 10 0mg/L～ 15 0 0mg/L范围内均具有良好的线性关系。所建立的方法对果糖、葡萄糖、蔗糖、海藻糖的检测下限分别为 10mg/L,2 0mg/L,10mg/L和 10mg/L。

建立高效液相色谱- 蒸发光散射法(HPLC-ELSD)同时测定食品中果糖、葡萄糖、蔗糖、麦芽糖和乳糖的方法。以Waters-NH2(4.6mm × 250mm，5μm)色谱柱；乙腈:水=75:25(V/V)为流动相，流速为1.0mL/min，ELSD为检测器，漂移管温度45℃，N2 流量25psi。待测组分与其他组分分离度良好(R ＞ 1.5)，果糖、葡萄糖、蔗糖、麦芽糖和乳糖在50～2000μg/mL 内有良好的线性关系，精密度RSD 小于3.8%，回收率大于80.3%。本方法在20min内完成了5 种糖的分离，结果比较理想，可作为糖类食品的质量控制和安全评价的测定方法。

食用型花生是我国乃至世界范围内花生育种的重要方向之一, 但是花生遗传改良中缺乏与食用品质相关的可溶性糖含量的快速检测方法, 限制了食用花生育种进展。本研究建立了80%乙醇和水浴快速提取花生籽仁可溶性糖的方法, 该提取方法与国标法相比, 简化了样品前期处理步骤, 加快了提取进度。通过准确性和重复性试验对该方法的验证表明, 该方法的重复性较好, 而且准确有效。以20份花生品种为材料, 利用高效液相-示差折光法对该方法提取的样品和国标法提取的样品进行检测发现, 成熟花生籽仁中的可溶性糖主要是蔗糖, 葡萄糖和果糖很少, 2种方法测定的结果差异不显著。利用本研究建立的方法检测20份花生品种的结果显示, 蔗糖含量最低为16.19 mg g^-1, 最高为83.81 mg g^-1, 平均为30.41 mg g^-1。利用国标法检测的结果显示, 蔗糖含量最低为15.60 mg g^-1, 最高为81.38 mg g^-1, 平均为30.20 mg g^-1。这些检测结果, 一方面进一步验证了所建立方法的实用性, 另一方面也表明这些花生品种中的蔗糖含量差异较大。

Galactinol synthase (EC 2.4.1.123; GolS) catalyzes the first step in the synthesis of raffinose family oligosaccharides (RFOs). Their accumulation in response to abiotic stresses implies a role for RFOs in stress adaptation. In this study, the expression patterns of three isoforms of galactinol synthase (CaGolS1-2-3) from Coffea arabica were evaluated in response to water deficit, salinity and heat stress. All CaGolS isoforms were highly expressed in leaves while little to no expression were detected in flower buds, flowers, plagiotropic shoots, roots, endosperm and pericarp of mature fruits. Transcriptional analysis indicated that the genes were differentially regulated under water deficit, high salt and heat stress. CaGolS1 isoform is constitutively expressed in plants under normal growth conditions and was the most responsive during all stress treatments. CaGolS2 is unique among the three isoforms in that it was detected only under severe water deficit and salt stresses. CaGolS3 was primarily expressed under moderate and severe drought. This isoform was induced only at the third day of heat and under high salt stress. The increase in GolS transcription was not reflected into the amount of galactinol in coffee leaves, as specific glycosyltransferases most likely used galactinol to transfer galactose units to higher homologous oligosaccharides, as suggested by the increase of raffinose and stachyose during the stresses.Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Sugar plays an essential role in plant cold acclimation (CA), but the interaction between CA and sugar remains unclear in tea plants. In this study, during the whole winter season, we investigated the variations of sugar contents and the expression of a large number of sugar-related genes in tea leaves. Results indicated that cold tolerance of tea plant was improved with the development of CA during early winter season. At this stage, starch was dramatically degraded, whereas the content of total sugars and several specific sugars including sucrose, glucose and fructose were constantly elevated. Beyond the CA stage, the content of starch was maintained at a low level during winter hardiness (WH) period and then was elevated during de-acclimation (DC) period. Conversely, the content of sugar reached a peak at WH stage followed by a decrease during DC stage. Moreover, gene expression results showed that, during CA period, sugar metabolism-related genes exhibited different expression pattern, in which beta-amylase gene (CsBAM), invertase gene (CsINV5) and raffinose synthase gene (CsRS2) engaged in starch, sucrose and raffinose metabolism respectively were solidly up-regulated; the expressions of sugar transporters were stimulated in general except the down-regulations of CsSWEET2, 3, 16, CsERD6.7 and CsINT2; interestingly, the sugar-signaling related CsHXK3 and CsHXK2 had opposite expression patterns at the early stage of CA. These provided comprehensive insight into the effects of CA on carbohydrates indicating that sugar accumulation contributes to tea plant cold tolerance during winter season, and a simply model of sugar regulation in response to cold stimuli is proposed.