Copper-induced proline synthesis is associated with nitric oxide generation in Chlamydomonas reinhardtii

Excess copper affects the growth and metabolism of plants and green algae. However, the physiological processes under Cu stress are largely unknown. In this study, we investigated Cu-induced nitric oxide (NO) generation and its relationship to proline synthesis in Chlamydomonas reinhardtii. The test alga accumulated a large amount of proline after exposure to relatively low Cu concentrations (2.5 and 5.0 microM Cu2+). A concomitant increase in the intracellular NO level was observed with increasing concentrations of Cu applied. Data analysis revealed that the endogenous NO generated was positively associated with the proline level in Cu-stressed algae. The involvement of NO in Cu-induced proline accumulation was confirmed by using an NO-specific donor, sodium nitroprusside (SNP), and an NO scavenger cPTIO [2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethylinidazoline-1-oxyl-3-oxide]. Pre-treatment with 10 microM SNP increased the proline accumulation in Cu-treated cells by about 1.5-fold, while this effect could be blocked by addition of 10 microM cPTIO. We further investigated the effect of Cu and NO on the activity and transcript amount of Delta(1)-pyrroline-5-carboxylate synthetase (P5CS, EC 2.7.2.11), the key enzyme of proline biosynthesis, and observed that application of SNP was able to stimulate the P5CS activity and up-regulate the expression of P5CS in the Cu-treated algae. These results indicate that Cu-responsive proline synthesis is closely related to NO generation in C. reinhardtii, suggesting the regulatory function of NO in proline metabolism under heavy metal stress.

Medienart:

E-Artikel

Erscheinungsjahr:

2008

Erschienen:

2008

Enthalten in:

Zur Gesamtaufnahme - volume:49

Enthalten in:

Plant & cell physiology - 49(2008), 3 vom: 18. März, Seite 411-9

Sprache:

Englisch

Beteiligte Personen:

Zhang, Li Ping [VerfasserIn]
Mehta, Surya Kant [VerfasserIn]
Liu, Zhao Pu [VerfasserIn]
Yang, Zhi Min [VerfasserIn]

Links:

Volltext

Themen:

31C4KY9ESH
789U1901C5
9DLQ4CIU6V
Copper
Journal Article
Nitric Oxide
Plant Proteins
Proline
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 23.06.2008

Date Revised 21.11.2013

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1093/pcp/pcn017

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM177406437