Overexpression of a carrot BCH gene, DcBCH1, improves tolerance to drought in Arabidopsis thaliana

Abstract Background Carrot (Daucus carota L.), an important root vegetable, is very popular among consumers as its taproot is rich in various nutrients. Abiotic stresses, such as drought, salt, and low temperature, are the main factors that restrict the growth and development of carrots. Non-heme carotene hydroxylase (BCH) is a key regulatory enzyme in the β-branch of the carotenoid biosynthesis pathway, upstream of the abscisic acid (ABA) synthesis pathway. Results In this study, we characterized a carrot BCH encoding gene, DcBCH1. The expression of DcBCH1 was induced by drought treatment. The overexpression of DcBCH1 in Arabidopsis thaliana resulted in enhanced tolerance to drought, as demonstrated by higher antioxidant capacity and lower malondialdehyde content after drought treatment. Under drought stress, the endogenous ABA level in transgenic A. thaliana was higher than that in wild-type (WT) plants. Additionally, the contents of lutein and β-carotene in transgenic A. thaliana were lower than those in WT, whereas the expression levels of most endogenous carotenogenic genes were significantly increased after drought treatment. Conclusions DcBCH1 can increase the antioxidant capacity and promote endogenous ABA levels of plants by regulating the synthesis rate of carotenoids, thereby regulating the drought resistance of plants. These results will help to provide potential candidate genes for plant drought tolerance breeding.

Download Full-text

Genetic Characterization of the Carotenoid Biosynthetic Pathway in Methylobacterium extorquens AM1 and Isolation of a Colorless Mutant

Applied and Environmental Microbiology ◽

10.1128/aem.69.12.7563-7566.2003 ◽

2003 ◽

Vol 69 (12) ◽

pp. 7563-7566 ◽

Cited By ~ 29

Author(s):

Stephen J. Van Dien ◽

Christopher J. Marx ◽

Brooke N. O'Brien ◽

Mary E. Lidstrom

Keyword(s):

Biosynthetic Pathway ◽

Genetic Characterization ◽

Carotenoid Biosynthesis ◽

Biosynthesis Pathway ◽

Wild Type ◽

Methylobacterium Extorquens ◽

Growth Properties ◽

Carotenoid Biosynthesis Pathway ◽

Free Strain

ABSTRACT Genomic searches were used to reconstruct the putative carotenoid biosynthesis pathway in the pink-pigmented facultative methylotroph Methylobacterium extorquens AM1. Four genes for putative phytoene desaturases were identified. A colorless mutant was obtained by transposon mutagenesis, and the insertion was shown to be in one of the putative phytoene desaturase genes. Mutations in the other three did not affect color. The tetracycline marker was removed from the original transposon mutant, resulting in a pigment-free strain with wild-type growth properties useful as a tool for future experiments.

Download Full-text

EPR study of thylakoid membrane dynamics in mutants of the carotenoid biosynthesis pathway of Synechocystis sp. PCC6803.

Acta Biochimica Polonica ◽

10.18388/abp.2012_2178 ◽

2012 ◽

Vol 59 (1) ◽

Cited By ~ 4

Author(s):

Kinga Kłodawska ◽

Przemysław Malec ◽

Mihály Kis ◽

Zoltán Gombos ◽

Kazimierz Strzałka

Keyword(s):

Optimal Growth ◽

Carotenoid Biosynthesis ◽

Growth Conditions ◽

Thylakoid Membranes ◽

Membrane Dynamics ◽

Biosynthesis Pathway ◽

Light Regimes ◽

Genes Encoding ◽

Splitting Parameter ◽

Carotenoid Biosynthesis Pathway

EPR spectroscopy using 5-doxylstearic acid (5-SASL) and 16-doxylstearic acid (16-SASL) spin probes was used to study the fluidity of thylakoid membranes. These were isolated from wild type Synechocystis and from several mutants in genes encoding selected enzymes of the carotenoid biosynthesis pathway and/or acyl-lipid desaturases. Cyanobacteria were cultivated at 25°C and 35°C under different light regimes: photoautotrophically (PAG) and/or in light-activated heterotrophic conditions (LAHG). The relative fluidity of membranes was estimated from EPR spectra based on the empirical outermost splitting parameter in a temperature range from 15°C to 40°C. Our findings demonstrate that in native thylakoid membranes the elimination of xanthophylls decreased fluidity in the inner membrane region under optimal growth conditions (25°C) and increased it under sublethal heat stress (35°C). This indicated that the overall fluidity of native photosynthetic membranes in cyanobacteria may be influenced by the ratio of polar to non-polar carotenoid pools under different environmental conditions.

Download Full-text

Predicting tomato field-yield using continuous monitoring of young tomato water status

10.1101/2021.03.18.435447 ◽

2021 ◽

Author(s):

Sanbon Gosa ◽

Amit Koch ◽

Itamar Shenhar ◽

Joseph Hirschberg ◽

Dani Zamir ◽

...

Keyword(s):

Prediction Models ◽

Water Status ◽

Total Yield ◽

Field Measurements ◽

Carotenoid Biosynthesis ◽

Yield Prediction ◽

Drought Treatment ◽

Recessive Mutations ◽

Tomato Yield ◽

Tomato Field

To address the challenge of predicting tomato yields in the field, we used whole-plant functional phenotyping to evaluate water relations under well-irrigated and drought conditions. The genotypes tested are known to exhibit variability in their yields in wet and dry fields. The examined lines included two lines with recessive mutations that affect carotenoid biosynthesis, zeta z2083 and tangerine t3406, both isogenic to the processing tomato variety M82. The two mutant lines were reciprocally grafted onto M82 and multiple physiological characteristics were measured continuously, as well as before, during and after drought treatment in the greenhouse. A comparative analysis of greenhouse and field yields showed that the whole-canopy stomatal conductance (gsc) in the morning and cumulative transpiration (CT) were strongly correlated with field measurements of total yield (TY: r2 = 0.9 and 0.77, respectively) and plant vegetative weight (PW: r2 = 0.6 and 0.94, respectively). Furthermore, the minimum CT during drought and the rate of recovery when irrigation was resumed were both found to predict resilience. Keywords: drought tolerance, functional genomic mapping, functional phenotyping, physiological trait, time-series measurements, tomato, yield prediction, yield-prediction models

Download Full-text

Transcriptome Analysis of Orange Head Chinese Cabbage (Brassica rapaL. ssp.pekinensis) and Molecular Marker Development

International Journal of Genomics ◽

10.1155/2017/6835810 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Jingjuan Li ◽

Yihui Zhang ◽

Qian Ding ◽

Huayin Li ◽

Lifeng Liu ◽

...

Keyword(s):

Chinese Cabbage ◽

Carotenoid Biosynthesis ◽

Underlying Mechanism ◽

Indel Marker ◽

Carotenoid Content ◽

Nucleotide Polymorphisms ◽

Visual Appearance ◽

Carotenoid Biosynthesis Pathway ◽

Molecular Marker Development ◽

Pigment Accumulation

Due to the visual appearance and high carotenoid content, orange inner leaves are a desirable trait for the Chinese cabbage. To understand the molecular mechanism underlying the formation of orange inner leaves, theBrCRTISO(Bra031539) gene, as theBr-orcandidate gene, was analyzed among the white and orange varieties, and 7 single nucleotide polymorphisms (SNPs) were identified. However, only one SNP (C952to T952) altered the amino acid sequence, resulting in a mutation from Leu318to Phe318in the orange varieties. Additionally, we analyzed differentially expressed genes (DEGs) between the orange and white F2individuals (14-401 × 14-490) and found four downregulated genes were involved in the carotenoid biosynthesis pathway, which may lead to the accumulation of prolycopene and other carotenoid pigments in the orange inner leaves. In addition, we developed a novel InDel marker in the first intron, which cosegregates with the phenotypes of orange color inner leaves. In conclusion, these findings enhance our understanding of the underlying mechanism of pigment accumulation in the inner leaves of the Chinese cabbage. Additionally, the SNP (C952to T952) and the InDel marker will facilitate the marker-assisted selection during Chinese cabbage breeding.

Download Full-text