Premium
Light influences cytokinin biosynthesis and sensing in Nostoc (cyanobacteria)
Author(s) -
Frébortová Jitka,
Plíhal Ondřej,
Florová Vendula,
Kokáš Filip,
Kubiasová Karolina,
Greplová Marta,
Šimura Jan,
Novák Ondřej,
Frébort Ivo
Publication year - 2017
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/jpy.12538
Subject(s) - cytokinin , biology , nostoc , histidine kinase , biochemistry , two component regulatory system , response regulator , gene , kinase , histidine , cyanobacteria , genetics , enzyme , bacteria , auxin , mutant
Cytokinins are an important group of plant hormones that are also found in other organisms, including cyanobacteria. While various aspects of cytokinin function and metabolism are well understood in plants, the information is limited for cyanobacteria. In this study, we first experimentally confirmed a prenylation of tRNA by recombinant isopentenyl transferase No IPT 2 from Nostoc sp. PCC 7120, whose encoding gene we previously identified in Nostoc genome along with the gene for adenylate isopentenyl transferase No IPT 1 . In contrast to No IPT 2 , the transcription of No IPT 1 was strongly activated during the dark period and was followed by an increase in the cytokinin content several hours later in the light period. Dominant cytokinin metabolites detected at all time points were free bases and monophosphates of isopentenyladenine and cis ‐zeatin, while N ‐glucosides were not detected at all. Whole transcriptome differential expression analysis of cultures of the above Nostoc strain treated by cytokinin compared to untreated controls indicated that cytokinin together with light trigger expression of several genes related to signal transduction, including two‐component sensor histidine kinases and two‐component hybrid sensors and regulators. One of the affected histidine kinases with a cyclase/histidine kinase‐associated sensory extracellular domain similar to the cytokinin‐binding domain in plant cytokinin receptors was able to modestly bind isopentenyladenine. The data show that the genetic disposition allows Nostoc not only to produce free cytokinins and prenylate tRNA but also modulate the cytokinin biosynthesis in response to light, triggering complex changes in sensing and regulation.