The drought response of Theobroma cacao (cacao) and the regulation of genes involved in polyamine biosynthesis by drought and other stresses. Plant Physiol Biochem

US Department of Agriculture/Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705, USA.
Plant Physiology and Biochemistry (Impact Factor: 2.76). 03/2008; 46(2):174-88. DOI: 10.1016/j.plaphy.2007.10.014
Source: PubMed


Drought can negatively impact pod production despite the fact that cacao production usually occurs in tropical areas having high rainfall. Polyamines (PAs) have been associated with the response of plants to drought in addition to their roles in responses to many other stresses. The constitutive and drought inducible expression patterns of genes encoding enzymes involved in PA biosynthesis were determined: an ornithine decarboxylase (TcODC), an arginine decarboxylase (TcADC), an S-adenosylmethionine decarboxylase (TcSAMDC), a spermidine synthase (TcSPDS), and a spermine synthase (TcSPMS). Expression analysis using quantitative real-time reverse transcription-PCR (QPCR) results showed that the PA biosynthesis genes were expressed in all plant tissues examined. Constitutive expression of PA biosynthesis genes was generally highest in mature leaves and open flowers. Expression of TcODC, TcADC, and TcSAMDC was induced with the onset of drought and correlated with changes in stomatal conductance, photosynthesis, photosystem II efficiency, leaf water potential and altered emission of blue-green fluorescence from cacao leaves. Induction of TcSAMDC in leaves was most closely correlated with changes in water potential. The earliest measured responses to drought were enhanced expression of TcADC and TcSAMDC in roots along with decreases in stomatal conductance, photosynthesis, and photosystem II efficiency. Elevated levels of putrescine, spermidine, and spermine were detected in cacao leaves 13days after the onset of drought. Expression of all five PA associated transcripts was enhanced (1.5-3-fold) in response to treatment with abscisic acid. TcODC and TcADC, were also responsive to mechanical wounding, infection by Phytophthora megakarya (a causal agent of black pod disease in cacao), the necrosis- and ethylene-inducing protein (Nep1) of Fusarium oxysporum, and flower abscission. TcSAMDC expression was responsive to all stresses except flower abscission. TcODC, although constitutively expressed at much lower levels than TcADC, TcSAMDC, TcSPDS, and TcSPMS, was highly inducible by the fungal protein Nep1 (135-fold) and the cacao pathogen Phytophthora megakarya (671-fold). The full length cDNA for ODC was cloned and characterized. Among the genes studied, TcODC, TcADC, and TcSAMDC were most sensitive to induction by drought in addition to other abiotic and biotic stresses. TcODC, TcADC, and TcSAMDC may share signal transduction pathways and/or the stress induced signal induction pathways may converge at these three genes leading to similar although not identical patterns of expression. It is possible altering PA levels in cacao will result in enhanced tolerance to multiple stresses including drought and disease as has been demonstrated in other crops.

Download full-text


Available from: Soo-Hyung Kim, Oct 01, 2015
44 Reads
  • Source
    • "QPCR was performed as described previously [22]. Mx3000P QPCR System (Agilent, Santa Clara, CA, USA) with SYBR Green QPCR Master Mix (LPS Solution, Daejeon, Korea) were used. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Cinnamoyl-CoA reductase (CCR) is an important enzyme for lignin biosynthesis as it catalyzes the first specific committed step in monolignol biosynthesis. We have cloned a full length coding sequence of CCR from kenaf (Hibiscus cannabinus L.), which contains a 1,020-bp open reading frame (ORF), encoding 339 amino acids of 37.37 kDa, with an isoelectric point (pI) of 6.27 (JX524276, HcCCR2). BLAST result found that it has high homology with other plant CCR orthologs. Multiple alignment with other plant CCR sequences showed that it contains two highly conserved motifs: NAD(P) binding domain (VTGAGGFIASWMVKLLLEKGY) at N-terminal and probable catalytic domain (NWYCYGK). According to phylogenetic analysis, it was closely related to CCR sequences of Gossypium hirsutum (ACQ59094) and Populus trichocarpa (CAC07424). HcCCR2 showed ubiquitous expression in various kenaf tissues and the highest expression was detected in mature flower. HcCCR2 was expressed differentially in response to various stresses, and the highest expression was observed by drought and NaCl treatments.
    The Scientific World Journal 02/2014; 2014(11, article 1471):601845. DOI:10.1155/2014/601845 · 1.73 Impact Factor
  • Source
    • "Polyamines (PAs) are small protonated compounds with key roles in plant development and stress protection (Urano et al., 2003; Hussain et al., 2011), of which the most predominant forms are the diamine putrescine (Put), triamine spermidine (Spd) and tetramine spermine (Spm) (Marco et al., 2011). In higher plants, there are two main pathways for the biosynthesis of PAs (Bae et al., 2008). In eukaryotic cells, Put is synthesised directly from ornithine through the activity of ornithine decarboxylase (ODC). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The accumulation of putrescine (Put) and increased arginine decarboxylase (ADC, EC activity levels in response to osmotic stress has been reported; however, the biological meaning of this increase remains unclear. To obtain new insights into these questions, we studied the drought response of a transgenic Lotus tenuis line that expresses the oat ADC gene, which is driven by the stress-inducible pRD29A promoter. This line contains high levels of Put with no changes in spermidine and spermine contents, even under water deficits. Our results indicate that the biochemical and morphological responses to dehydration correlate with the Put level and provide evidence that Put controls the ABA content in response to drought by modulating ABA biosynthesis at the transcriptional level.
    Plant Physiology and Biochemistry 01/2014; 76C:29-35. DOI:10.1016/j.plaphy.2013.12.018 · 2.76 Impact Factor
  • Source
    • "Both 5 í® í° and 3 í® í° RACE kits were used to clone a full length of F5H ortholog following the manufacturer's instructions (Invitrogen). QPCR was performed as previously described [24] using the Mx3000P QPCR System (Agilent, Santa Clara, CA, USA) with SYBR Green QPCR Master Mix (LPS Solution, Daejeon, Korea). F5H primers used for QPCR were as follows: forward primer, 5 í® í° "
    [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study is to clone and characterize the expression pattern of a F5H gene encoding ferulate 5-hydroxylase in the phenylpropanoid pathway from kenaf (Hibiscus cannabinus L.). Kenaf is a fast-growing dicotyledonous plant valued for its biomass. F5H, a cytochrome P450-dependent monooxygenase (CYP84), is a key enzyme for syringyl lignin biosynthesis. The full length of the F5H ortholog was cloned and characterized. The full-length F5H ortholog consists of a 1,557-bp open reading frame (ORF) encoding 518 amino acids (GenBank Accession number JX524278). The deduced amino acid sequence showed that kenaf F5H had the highest similarity (78%) with that of Populus trichocarpa. Transcriptional analysis of F5H ortholog was conducted using quantitative real-time PCR during the developmental stages of various tissues and in response to various abiotic stresses. The highest transcript level of the F5H ortholog was observed in immature flower tissues and in early stage (6 week-old) of stem tissues, with a certain level of expression in all tissues tested. The highest transcript level of F5H ortholog was observed at the late time points after treatments with NaCl (48 h), wounding (24 h), cold (24 h), abscisic acid (24 h), and methyl jasmonate (24 h).
    The Scientific World Journal 09/2013; 2013(3):421578. DOI:10.1155/2013/421578 · 1.73 Impact Factor
Show more