Comparative analysis of the heat stable proteome of radicles of Medicago truncatula seeds during germination identifies late embryogenesis abundant proteins associated with desiccation tolerance
Comparative analysis of the heat stable proteome of radicles of Medicago truncatula seeds during germination identifies late embryogenesis abundant proteins associated with desiccation tolerance
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DOI：
10.1104/pp.105.074039
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发表时间：
2006-04-01
期刊：
影响因子：
7.4
通讯作者：
Leprince, O
中科院分区：
文献类型：
--
作者：
Boudet, J;Buitink, J;Leprince, O
对蒺藜苜蓿种子吸胀胚根的热稳定蛋白组分进行蛋白质组学分析，以研究是否可以鉴定出与脱水耐性（DT）特异性相关的蛋白质。胚根进行了比较之前和之后出现（2.8毫米长）与DT的损失，并通过渗透处理后的DT reinduction。为了将渗透处理诱导的蛋白质与DT相关的蛋白质分开，将比较扩展到5 mm长的出现的胚根，对于这些胚根，DT不再被再诱导，尽管耐旱性增加。15种多肽的丰度与DT相关，其中11种被鉴定为来自不同组的晚期胚胎发生丰富蛋白：MtEm 6（组1）、DHN 3的一种同种型（β-葡聚糖）、MtPM 25（组5）和组3的三个成员（MP2、PM 18的一种同种型和SBP 65的所有同种型）。计算机模拟分析显示，它们的表达可能是种子特异性的，除了DHN 3。其它的DNH 3和PM 18以及Budcar 5中的3种DNH 3同工型与耐旱性相关。在吸胀子叶中的MT EM 6和MT PM 25的丰度的变化期间的损失DT和发育中的胚胎在收购DT证实了这两种蛋白质与DT的链接。傅里叶变换红外光谱显示，重组MtPM 25和MtEm 6在水合状态下表现出一定程度的秩序，但它们在干燥过程中通过采用α螺旋和β折叠而变得更加结构化。一个模型中，DT-连接的晚期胚胎发生丰富的蛋白质可能会发挥不同的保护功能，在高和低水化水平。
A proteomic analysis was performed on the heat stable protein fraction of imbibed radicles of Medicago truncatula seeds to investigate whether proteins can be identified that are specifically linked to desiccation tolerance (DT). Radicles were compared before and after emergence (2.8 mm long) in association with the loss of DT, and after reinduction of DT by an osmotic treatment. To separate proteins induced by the osmotic treatment from those linked with DT, the comparison was extended to 5 mm long emerged radicles for which DT could no longer be reinduced, albeit that drought tolerance was increased. The abundance of 15 polypeptides was linked with DT, out of which 11 were identified as late embryogenesis abundant proteins from different groups: MtEm6 (group 1), one isoform of DHN3 (dehydrins), MtPM25 (group 5), and three members of group 3 (MP2, an isoform of PM18, and all the isoforms of SBP65). In silico analysis revealed that their expression is likely seed specific, except for DHN3. Other isoforms of DNH3 and PM18 as well as three isoforms of the dehydrin Budcar5 were associated with drought tolerance. Changes in the abundance of MtEm6 and MtPM25 in imbibed cotyledons during the loss of DT and in developing embryos during the acquisition of DT confirmed the link of these two proteins with DT. Fourier transform infrared spectroscopy revealed that the recombinant MtPM25 and MtEm6 exhibited a certain degree of order in the hydrated state, but that they became more structured by adopting alpha helices and beta sheets during drying. A model is presented in which DT-linked late embryogenesis abundant proteins might exert different protective functions at high and low hydration levels.