Occurrence, structure, and evolution of nitric oxide synthase–like proteins in the plant kingdom

Abstract

Nitric oxide (NO) signaling regulates various physiological processes in both animals and plants. In animals, NO synthesis is mainly catalyzed by NO synthase (NOS) enzymes. Although NOS-like activities that are sensitive to mammalian NOS inhibitors have been detected in plant extracts, few bona fide plant NOS enzymes have been identified. We searched the data set produced by the 1000 Plants (1KP) international consortium for the presence of transcripts encoding NOS-like proteins in over 1000 species of land plants and algae. We also searched for genes encoding NOS-like enzymes in 24 publicly available algal genomes. We identified no typical NOS sequences in 1087 sequenced transcriptomes of land plants. In contrast, we identified NOS-like sequences in 15 of the 265 algal species analyzed. Even if the presence of NOS enzymes assembled from multipolypeptides in plants cannot be conclusively discarded, the emerging data suggest that, instead of generating NO with evolutionarily conserved NOS enzymes, land plants have evolved finely regulated nitrate assimilation and reduction processes to synthesize NO through a mechanism different than that in animals.

Sulfur deprivation-induced expression of THB1, a Chlamydomonas reinhardtii truncated hemoglobin, is mediated by nitrate reductase-dependent NO production

“…Given that NO is generated in S-deprived cells (Minaeva et al, 2017), the increase in THB1 transcription detected during S limitation may reflect NOS activity. Recently, several algae were shown to contain NOS (Foresi et al, 2010;Jeandroz et al, 2016). This, however, did not appear to be the case in our experiments.…”

“…In Chlamydomonas, it has been reported that THB1 is induced by nitrate (Johnson et al, 2014). Moreover, THB1 is highly expressed in the presence of NO (Sanz-Luque et al, 2015).…”

A Comprehensive Phylogeny Reveals Functional Conservation of the UV-B Photoreceptor UVR8 from Green Algae to Higher Plants

“…Taxons where this protein was identified are indicated in parenthesis after the name of each group. The image has been taken and adapted from Jeandroz et al (2016) and Rensing (2016).…”

A positive role for hydrogen gas in adventitious root development

“…27 Our previous research have found that hydrogen peroxide, NO, Ca 2C ions and calmodulin were involved in adventitious root development. 38 suggesting that NR-associated NO production is main pathway involved in H 2 -induced rooting. Three rootingrelated enzymes, peroxidase, polyphenol oxidas and indoleacetic acid oxidase were involved in H 2 -indcued adventitious rooting through NO pathways.…”