TY - JOUR

T1 - Impact of nitric oxide on prolific, and putrescine biosynthesis in Chlamydomonas via transcriptional regulation

AU - Zalutskaya, Z.

AU - Derkach, V.

AU - Puzanskiy, R.

AU - Ermilova, E.

N1 - Publisher Copyright: © 2020, Institute of Experimental Botany, ASCR. All rights reserved. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020

Y1 - 2020

N2 - Nitric oxide plays an important role in regulating adaption of the model alga Chlamydomonas reinhardtii to various environmental stresses. One response to abiotic stresses is the accumulation of protective molecules such as proline and putrescine. The NO treatment led to a significant accumulation of proline in cells. Quantitative real-time expression analysis of proline metabolic genes in NO-treated cells showed a prolonged upregulation of the gene encoding γ-glutamyl kinase 1 (GGK1) in the glutamate biosynthetic pathway. Furthermore, truncated hemoglobin 2 (THB2)-underexpressing strains with an enhanced endogenous NO demonstrated a higher proline content and GGK1 mRNA abundances than the wild type. In contrast, transcription of the gene encoding ornithine δ-aminotransferase in the ornithine pathway of proline biosynthesis decreased after treatment with NO. This suggests the predominance of the glutamate pathway over the ornithine pathway. We also found that the expression of the proline dehydrogenase gene encoding a key enzyme in proline catabolism was downregulated in NO-treated cells. Chlamydomonas reinhardtii exposed to exogenous NO also showed an increased ornithine decarboxylase 2 mRNA and putrescine content. Our findings indicate a clear link between changes in NO application and proline and putrescine content via transcriptional regulation of respective enzymes.

AB - Nitric oxide plays an important role in regulating adaption of the model alga Chlamydomonas reinhardtii to various environmental stresses. One response to abiotic stresses is the accumulation of protective molecules such as proline and putrescine. The NO treatment led to a significant accumulation of proline in cells. Quantitative real-time expression analysis of proline metabolic genes in NO-treated cells showed a prolonged upregulation of the gene encoding γ-glutamyl kinase 1 (GGK1) in the glutamate biosynthetic pathway. Furthermore, truncated hemoglobin 2 (THB2)-underexpressing strains with an enhanced endogenous NO demonstrated a higher proline content and GGK1 mRNA abundances than the wild type. In contrast, transcription of the gene encoding ornithine δ-aminotransferase in the ornithine pathway of proline biosynthesis decreased after treatment with NO. This suggests the predominance of the glutamate pathway over the ornithine pathway. We also found that the expression of the proline dehydrogenase gene encoding a key enzyme in proline catabolism was downregulated in NO-treated cells. Chlamydomonas reinhardtii exposed to exogenous NO also showed an increased ornithine decarboxylase 2 mRNA and putrescine content. Our findings indicate a clear link between changes in NO application and proline and putrescine content via transcriptional regulation of respective enzymes.

KW - Glutamyl kinase

KW - Ornithine decarboxylase

KW - Polyamines

KW - Truncated hemoglobins

KW - HEMOGLOBIN

KW - truncated hemoglobins

KW - ORNITHINE-DECARBOXYLASE

KW - METABOLISM

KW - glutamyl kinase

KW - GENE-EXPRESSION

KW - ornithine decarboxylase

KW - PLANTS

KW - STARVATION

KW - polyamincs

KW - ACCUMULATION

KW - STRESS

KW - INSIGHTS

UR - http://www.scopus.com/inward/record.url?scp=85094566731&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/7213c54e-21d8-32e3-ab53-26613214784a/

U2 - DOI: 10.32615/bp.2020.094

DO - DOI: 10.32615/bp.2020.094

M3 - Article

AN - SCOPUS:85094566731

VL - 64

SP - 642

EP - 648

JO - Biologia Plantarum

JF - Biologia Plantarum

SN - 0006-3134

ER -