Nutrient limitation is the main regulatory factor for carotenoid accumulation and for Psy and Pds steady state transcript levels in Dunaliella salina (Chlorophyta) exposed to high light and salt stress. | - CCMAR -

Journal Article

TítuloNutrient limitation is the main regulatory factor for carotenoid accumulation and for Psy and Pds steady state transcript levels in Dunaliella salina (Chlorophyta) exposed to high light and salt stress.
Publication TypeJournal Article
AuthorsCoesel, SNicole, Baumgartner, ACordeiro, Teles, LMarlene, Ramos, AA, Henriques, NMiguel, M. Cancela, L, Varela, J
Year of Publication2008
JournalMar Biotechnol (NY)
Volume10
Questão5
Date Published2008 Sep-Oct
Pagination602-11
ISSN1436-2228
Palavras-chaveAlkyl and Aryl Transferases, Carotenoids, Chlorophyta, Culture Media, Food, Gene Expression Regulation, Geranylgeranyl-Diphosphate Geranylgeranyltransferase, Light, Nitrates, Oxidoreductases, RNA, Messenger, Sodium Chloride, Time Factors
Abstract

Dunaliella salina (Dunal) Teodoresco (1905) is a green unicellular alga able to withstand severe salt, light, and nutrient stress, adaptations necessary to grow in harsh environments such as salt ponds. In response to such growth conditions, this microalga accumulates high amounts of beta-carotene in its single chloroplast. In this study, we show that carotenoid accumulation is consistently inhibited in cells grown in nutrient-supplemented media and exposed either to high-light or medium-low-light conditions. Likewise, carotenogenesis in cells shifted to higher salinity (up to 27% NaCl) under medium-low-light conditions is inhibited by the presence of nutrients. The steady-state levels of transcripts encoding phytoene synthase and phytoene desaturase increased substantially in D. salina cells shifted to high light or high salt under nutrient-limiting conditions, whereas the presence of nutrients inhibited this response. The regulatory effect of nutrient availability on the accumulation of carotenoids and messenger RNA levels of the first two enzymes committed to carotenoid biosynthesis is discussed.

DOI10.1007/s10126-008-9100-2
Sapientia

http://www.ncbi.nlm.nih.gov/pubmed/18449600?dopt=Abstract

Alternate JournalMar. Biotechnol.
PubMed ID18449600