Arabinogalactan protein profiles and distribution patterns during microspore embryogenesis and pollen development in Brassica napus
Arabinogalactan protein profiles and distribution patterns during microspore embryogenesis and pollen development in Brassica napus
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DOI：
10.1007/s00497-013-0217-8
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发表时间：
2013-09-01
影响因子：
3.4
通讯作者：
Testillano, Pilar S.
中科院分区：
文献类型：
--
作者：
El-Tantawy, Ahmed-Abdalla;Solis, Maria-Teresa;Testillano, Pilar S.
阿拉伯半乳聚糖蛋白（ArabinogalactanProteins，AGPs）是存在于植物细胞壁、质膜和细胞外分泌物中的一类富含羟脯氨酸的糖基化蛋白，在植物的发育过程中起着重要作用。在胁迫处理后，体外培养的小孢子可以重新编程并改变其配子体发育途径，从而产生胚胎，这些胚胎可以进一步产生单倍体和双单倍体植物，这是植物育种中重要的生物技术工具。小孢子胚胎发生是研究细胞重编程和胚胎形成机制的一个便利系统。在这项工作中，AGP的存在和分布的动态在甘蓝型油菜花粉发育和小孢子胚胎发生过程中，通过采用多学科的方法，使用单克隆抗体的AGP（LM 2，LM 6，JIM 13，JIM 14，MAC 207）和分析的BnAGP Sta 39-4基因的表达模式。结果表明，发育调节和确定的定位研究的AGP表位在两个小孢子发育途径，揭示不同的分布模式，具有不同的抗原反应性的AGP。JIM 13、JIM 14和MAC 207抗体识别的AGPs与花粉成熟有关，而LM 2和LM 6标记的AGPs与胚胎发育有关。有趣的是，由JIM 13和JIM 14标记的AGP随着小孢子命运的改变而被诱导。在2-4细胞期胚胎细胞壁中特异性发现的Sta 39-4基因、JIM 13和JIM 14表位的表达增加表明AGP是小孢子胚胎发生的早期分子标记。后来，LM 2和LM 6抗原随着胚胎发育而逐渐增加，并定位于细胞壁和细胞质斑点上，表明在体外胚胎形成过程中AGPs的活跃产生和分泌。这些结果提供了新的见解参与的AGPs作为潜在的调节/信号分子在小孢子重编程和胚胎发生。
Arabinogalactan proteins (AGPs), present in cell walls, plasma membranes and extracellular secretions, are massively glycosylated hydroxyproline-rich proteins that play a key role in several plant developmental processes. After stress treatment, microspores cultured in vitro can reprogramme and change their gametophytic developmental pathways towards embryogenesis, thereby producing embryos which can further give rise to haploid and double haploid plants, important biotechnological tools in plant breeding. Microspore embryogenesis constitutes a convenient system for studying the mechanisms underlying cell reprogramming and embryo formation. In this work, the dynamics of both AGP presence and distribution were studied during pollen development and microspore embryogenesis in Brassica napus, by employing a multidisciplinary approach using monoclonal antibodies for AGPs (LM2, LM6, JIM13, JIM14, MAC207) and analysing the expression pattern of the BnAGP Sta 39-4 gene. Results showed the developmental regulation and defined localization of the studied AGP epitopes during the two microspore developmental pathways, revealing different distribution patterns for AGPs with different antigenic reactivity. AGPs recognized by JIM13, JIM14 and MAC207 antibodies were related to pollen maturation, whereas AGPs labelled by LM2 and LM6 were associated with embryo development. Interestingly, the AGPs labelled by JIM13 and JIM14 were induced with the change of microspore fate. Increases in the expression of the Sta 39-4 gene, JIM13 and JIM14 epitopes found specifically in 2-4 cell stage embryo cell walls, suggested that AGPs are early molecular markers of microspore embryogenesis. Later, LM2 and LM6 antigens increased progressively with embryo development and localized on cell walls and cytoplasmic spots, suggesting an active production and secretion of AGPs during in vitro embryo formation. These results give new insights into the involvement of AGPs as potential regulating/signalling molecules in microspore reprogramming and embryogenesis.