Identification and characterization of small RNAs from the phloem of Brassica napus
Identification and characterization of small RNAs from the phloem of Brassica napus
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DOI：
10.1111/j.1365-313x.2007.03368.x
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发表时间：
2008-03-01
期刊：
影响因子：
7.2
通讯作者：
Kehr, Julia
中科院分区：
文献类型：
--
作者：
Buhtz, Anja;Springer, Franziska;Kehr, Julia
系统信号是不可或缺的发展，防御和营养分配过程中的各种生理过程的协调。间接证据表明，植物小RNA（smRNAs）可能参与通过植物的脉管系统的长距离信息传递。对油菜（Brassica napus）维管分泌物的smRNA互补物的分析表明，木质部汁液中没有RNA，而韧皮部汁液中含有大量的smRNA。除了可以鉴定和批准的来自18个不同家族的32种注释的microRNA（miRNAs）之外，还获得了一组未知的smRNAs，主要长度为21和24个核苷酸，并且发现所选择的候选者在韧皮部汁液中高度丰富。此外，我们可以证明，在相应的饥饿条件下，在植物的生长过程中，在非维管组织中，miR395（硫酸盐），miR398（铜）和miR399（磷酸盐），三种已知响应营养剥夺的miRNAs的水平在韧皮部汁液中增加。有趣的是，只有成熟的miRNA分子被发现是应激反应，这表明单链正义miRNA最有可能代表生理相关分子。韧皮部中的强烈反应表明miRNA通过这种长距离运输系统在系统信息传递中的作用。
Systemic signalling is indispensable for the coordination of diverse physiological processes during development, defence and nutrient allocation. Indirect evidence suggests that plant small RNAs (smRNAs) could be involved in long-distance information transfer via the vasculature of the plant. Analyses of the smRNA complements of vascular exudates from oilseed rape (Brassica napus) showed that xylem sap is devoid of RNA, whereas phloem sap contained a large number of smRNAs. In addition to 32 annotated microRNAs (miRNAs) from 18 different families that could be identified and approved, a set of unknown smRNAs, predominantly of 21 and 24 nucleotides in length, was obtained, and selected candidates were found to be highly abundant in phloem sap. Moreover, we could demonstrate that the levels of three miRNAs known to respond to nutrient deprivation in non-vascular tissue, miR395 (sulphate), miR398 (copper) and miR399 (phosphate), were increased in phloem sap during the growth of plants under the respective starvation conditions. Interestingly, only mature miRNA molecules were found to be stress responsive, demonstrating that single-stranded sense miRNAs are most likely to represent the physiologically relevant molecules. The strong responses in the phloem suggest a role of miRNAs in systemic information transfer via this long-distance transport system.