PT  - JOURNAL ARTICLE
AU  - Aleksandra Swida-Barteczka
AU  - Anja Krieger-Liszkay
AU  - Wolfgang Bilger
AU  - Ulrike Voigt
AU  - Götz Hensel
AU  - Zofia Szweykowska-Kulinska
AU  - Karin Krupinska
TI  - The plastid-nucleus located DNA/RNA binding protein WHIRLY1 regulates microRNA-levels during stress
AID  - 10.1101/197202
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 197202
4099  - http://biorxiv.org/content/early/2017/10/02/197202.short
4100  - http://biorxiv.org/content/early/2017/10/02/197202.full
AB  - In this article a novel mechanism of retrograde signaling by chloroplasts during stress is described. This mechanism involves the DNA/RNA binding protein WHIRLY1 as a regulator of microRNA levels. By virtue of its dual localization in chloroplasts and the nucleus of the same cell, WHIRLY1 was proposed as an excellent candidate coordinator of chloroplast function and nuclear gene expression (Grabowski et al., 2008; Foyer et al., 2014). In this study the putative involvement of WHIRLY1 in stress dependent retrograde signaling was investigated by comparison of barley (Hordeum vulgare L., cv. Golden Promise) wild-type and transgenic plants with an RNAi-mediated knockdown of WHIRLY1. In contrast to the wild type, the transgenic plants were unable to cope with continuous high light conditions. They were impaired in production of several microRNAs mediating post-transcriptional responses during stress (Kruszka et al., 2012, Sunkar et al., 2012). The results support a central role of WHIRLY1 in retrograde signaling and underpin a so far underestimated role of microRNAs in this process.