Anthoceros agrestis Journal Article Cyanobiont DYW domain GFP Nostoc punctiforme PPR proteins PPR-RNA binding code Plant Proteins RNA editing factors RNA, Plant Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. biological nitrogen fixation chloroplast DNA fluorescence hormogonia hormogonia inducing factor mitochondrial DNA nitrogen fixation plant-symbiosis reverse U-to-C RNA editing