Isolation and characterization of multiple abundant lipid transfer protein isoforms in developing sesame (Sesamum indicum L.) seeds
Isolation and characterization of multiple abundant lipid transfer protein isoforms in developing sesame (Sesamum indicum L.) seeds
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DOI：
10.1016/j.plaphy.2007.10.003
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发表时间：
2008-02-01
影响因子：
6.5
通讯作者：
Suh, Mi Chung
中科院分区：
文献类型：
--
作者：
Choi, Ah Mi;Lee, Saet Buyl;Suh, Mi Chung
芝麻（Sesamum indicum）是一种重要的油料作物，约50%的种子干重是储存油。在以前的报告中，开发芝麻种子表达序列标签（ESTs）显示，编码脂质转运蛋白（LTP）的ESTs是芝麻ESTs中最丰富的群体之一。LTP在蜡或角质单体的转移和对病原体攻击的防御反应中起作用。为了研究种子发育过程中丰富的UP异构体的生物学作用，从3328个芝麻EST中选取122个EST与拟南芥和水稻蛋白质组数据库进行比对分析。UP馏分，这是部分纯化的发展中的芝麻种子，积极转移荧光磷脂和结合脂肪酸。分离出21种UP同工型中的5种的全长cDNA，并命名为SiLTP 1-SiLTP 5。预测的5个SiLTP的氨基酸序列具有LTP的典型特征，包括半胱氨酸残基的保守排列。北方印迹分析表明，这5种SiLTP亚型在发育中的种子中表达量最高，但在花组织中也有表达。此外，SiLTP 3和SiLTP 4的成绩单表达在叶片和种子盆壁，分别。此外，SiLTP 2和SiLTP 4转录显着诱导6日龄芝麻幼苗的NaCl，甘露醇，脱落酸（阿坝）的应用。在拟南芥原生质体中瞬时表达绿色荧光蛋白（GFP）融合构建体揭示了SiLTP 1和SiLTP 2通过不同的途径分泌。总之，芝麻籽中丰富的LTP参与了脂质转移到细胞外基质中。可能的生物学作用的SiLTP器官特异性表达和非生物胁迫进行了讨论。(c)2007年，Elsevier Masson SAS。All rights reserved.
Sesame (Sesamum indicum) is an important oilseed crop; approximately 50% of the seed dry weight is storage oil. In a previous report, developing sesame seed expressed sequence tags (ESTs) revealed that ESTs encoding lipid transfer protein (LTPs) were one of the most abundant groups of sesame ESTs. LTP functions in the transfer of wax or cutin monomers and in the defense response against pathogen attack. To study the biological role of the abundant UP isoforms in developing seeds, 122 ESTs out of 3328 sesame ESTs were analyzed against Arabidopsis and rice proteome databases. UP fraction, which was partially purified from developing sesame seeds, actively transferred fluorescent phospholipids and bound to fatty acids. Full-length cDNAs of five out of 21 UP isoforms were isolated and named SiLTP1-SiLTP5. The predicted amino acid sequences of the five SiLTPs harbor typical characteristics of LTPs, including conserved arrangement of cysteine residues. Northern blot analysis revealed that the five SiLTP isoforms were most abundantly expressed in developing seeds, but were also detected in flower tissues. Also, SiLTP3 and SiLTP4 transcripts were expressed in leaves and seed-pot walls, respectively. In addition, SiLTP2 and SiLTP4 transcripts were significantly induced in 6-day-old sesame seedlings by application of NaCl, mannitol, and abscisic acid (ABA). Transient expression of green fluorescent protein (GFP)-fusion constructs in Arabidopsis protoplasts revealed that SiLTP1 and SiLTP2 were secreted by different pathways. Taken together, the abundant LTPs in developing sesame seeds are involved in lipid transfer into the extracellular matrix. Possible biological roles of SiLTPs related to organ-specific expression and abiotic stresses are discussed. (c) 2007 Elsevier Masson SAS. All rights reserved.