Graft‐transmissible movement of inverted‐repeat‐induced siRNA signals into flowers. (14th August 2014)

• Record Type: Journal Article
• Authors: Zhang, Wenna; Kollwig, Gregor; Stecyk, Ewelina; Apelt, Federico; Dirks, Rob; Kragler, Friedrich
• Is Part Of: Plant journal. Volume 80:Number 1(2014:Oct.)
• Page Start: 106
• Page End: 121
• Publication Date: 2014-08-14
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12622
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12622-abs-0001"> <title>Summary</title> <p>In plants, small interfering RNAs (siRNA) and microRNAs move to distant tissues where they control numerous developmental and physiological processes such as morphogenesis and stress responses. Grafting techniques and transient expression systems have been employed to show that sequence‐specific siRNAs with a size of 21–24 nucleotides traffic to distant organs. We used inverted‐repeat constructs producing siRNA targeting the meiosis factor <italic>DISRUPTED MEIOTIC cDNA 1</italic> (<italic>DMC1</italic>) and <italic>GFP</italic> to test whether silencing signals move into meiotically active tissues. In grafted <italic>Nicotiana tabacum</italic>, a transgenic <italic>DMC1</italic> siRNA signal made in source tissues preferably entered the anthers formed in the first flowers. Here, the <italic>DMC1</italic> siRNA interfered with meiotic progression and, consequently, the flowers were at least partially sterile. In agro‐infiltrated <italic>N. benthamiana</italic> plants, a <italic>GFP</italic> siRNA signal produced in leaves was allocated and active in most flower tissues including anthers. In hypocotyl‐grafted <italic>Arabidopsis thaliana</italic> plants, the <italic>DMC1</italic> silencing signal consistently appeared in leaves, petioles, and stem, and only a small number of plants displayed <italic>DMC1</italic> siRNA signals in flowers. In all three tested plant species the systemic silencing signal penetrated male sporogenic tissues suggesting that plants harbour an endogenous long‐distance small RNA transport pathway facilitating siRNA signalling into meiotically active cells.</p> </abstract>