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Gao H.,Beijing Forestry University | Gao H.,National Engineering Laboratory for Tree Breeding | Gao H.,Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education | Gao F.,Beijing Forestry University
Frontiers in Biology | Year: 2011

Chloroplasts are photosynthetic organelles derived from endosymbiotic cyanobacteria during evolution. Dramatic changes occurred during the process of the formation and evolution of chloroplasts, including the large-scale gene transfer from chloroplast to nucleus. However, there are still many essential characters remaining. For the chloroplast division machinery, FtsZ proteins, Ftn2, SulA and part of the division site positioning system-MinD and MinE are still conserved. New or at least partially new proteins, such as FtsZ family proteins FtsZ1 and ARC3, ARC6H, ARC5, PDV1, PDV2 and MCD1, were introduced for the division of chloroplasts during evolution. Some bacterial cell division proteins, such as FtsA, MreB, Ftn6, FtsW and FtsI, probably lost their function or were gradually lost. Thus, the chloroplast division machinery is a dynamically evolving structure with both conservation and innovation. © 2011 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Gao Y.,Beijing Forestry University | Liu H.,Beijing Forestry University | An C.,Beijing Forestry University | Shi Y.,Beijing Forestry University | And 7 more authors.
Plant Journal | Year: 2013

ARC5 is a dynamin-related GTPase essential for the division of chloroplasts in plants. The arc5 mutant frequently exhibits enlarged, dumbbell-shaped chloroplasts, indicating a role for ARC5 in the constriction of the chloroplast division site. In a screen for chloroplast division mutants with a phenotype similar to arc5, two mutants, cpd25 and cpd45, were obtained. CPD45 was identified as being the same gene as FHY3, a key regulator of far-red light signaling recently shown to be involved in the regulation of ARC5. CPD25 was previously named FRS4 and is homologous to FHY3. We found that CPD25 is also required for the expression of ARC5, suggesting that its function is not redundant to that of FHY3. Moreover, cpd25 does not have the far-red light-sensing defect present in fhy3 and far1. Both FRS4/CPD25 and FHY3/CPD45 could bind to the FBS-like 'ACGCGC' motifs in the promoter region of ARC5, and the binding efficiency of FRS4/CPD25 was much higher than that of FHY3/CPD45. Unlike FHY3/CPD45, FRS4/CPD25 has no ARC5 activation activity. Our data suggest that FRS4/CPD25 and FHY3/CPD45 function as a heterodimer that cooperatively activates ARC5, that FRS4/CPD25 plays the major role in promoter binding, and that FHY3/CPD45 is largely responsible for the gene activation. This study not only provides insight into the mechanisms underlying the regulation of chloroplast division in higher plants, but also suggests a model that shows how members of a transcription factor family can evolve to have different DNA-binding and gene activation features. © 2013 John Wiley & Sons Ltd.

Chao N.,Beijing Forestry University | Liu S.-X.,Beijing Forestry University | Liu B.-M.,Beijing Forestry University | Li N.,Beijing Forestry University | And 5 more authors.
Planta | Year: 2014

Main conclusion: Nine CAD/CAD-like genes inP. tomentosawere classified into four classes based on expression patterns, phylogenetic analysis and biochemical properties with modification for the previous claim of SAD.Cinnamyl alcohol dehydrogenase (CAD) functions in monolignol biosynthesis and plays a critical role in wood development and defense. In this study, we isolated and cloned nine CAD/CAD-like genes in the Populus tomentosa genome. We investigated differential expression using microarray chips and found that PtoCAD1 was highly expressed in bud, root and vascular tissues (xylem and phloem) with the greatest expression in the root. Differential expression in tissues was demonstrated for PtoCAD3, PtoCAD6 and PtoCAD9. Biochemical analysis of purified PtoCADs in vitro indicated PtoCAD1, PtoCAD2 and PtoCAD8 had detectable activity against both coniferaldehyde and sinapaldehyde. PtoCAD1 used both substrates with high efficiency. PtoCAD2 showed no specific requirement for sinapaldehyde in spite of its high identity with so-called PtrSAD (sinapyl alcohol dehydrogenase). In addition, the enzymatic activity of PtoCAD1 and PtoCAD2 was affected by temperature. We classified these nine CAD/CAD-like genes into four classes: class I included PtoCAD1, which was a bone fide CAD with the highest activity; class II included PtoCAD2, -5, -7, -8, which might function in monolignol biosynthesis and defense; class III genes included PtoCAD3, -6, -9, which have a distinct expression pattern; class IV included PtoCAD12, which has a distinct structure. These data suggest divergence of the PtoCADs and its homologs, related to their functions. We propose genes in class II are a subset of CAD genes that evolved before angiosperms appeared. These results suggest CAD/CAD-like genes in classes I and II play a role in monolignol biosynthesis and contribute to our knowledge of lignin biosynthesis in P. tomentosa. © 2014, Springer-Verlag Berlin Heidelberg.

Zhou P.,Shanghai JiaoTong University | Zhu Q.,National Engineering Laboratory for Tree Breeding | Zhu Q.,Beijing Forestry University | Xu J.,National Engineering Laboratory for Tree Breeding | And 3 more authors.
Crop Science | Year: 2011

Expansin proteins play a role in regulating cell growth and plant adaptation to various environmental stresses. The objectives of this study were to clone and characterize the expression and promoter activity of a gene in creeping bentgrass (Agrostis stolonifera L.) encoding an expansin protein, AsEXP1, in response to heat stress and plant hormones. The AsEXP1 cloned from the genome of heat-tolerant genotype 'Penn A-4' spans a 2659 bp DNA sequence and consists of three coding sequences, two introns, a 962 bp 5'-noncoding region, and a 483 bp 3'-noncoding region. Several putative abscisic acid (ABA)-response cis-elements and gibberellic acid (GA)-response cis-elements were found nearby TATA box in the promoter region through the search of PlantCARE database and PLACE database search. AsEXP1 transcripts were detected by reverse transcription polymerase chain reaction (RT-PCR) in Penn A-4 leaves treated with ABA and GA, while no transcripts were detected in untreated plants. The AsEXP1 promoter was cloned into a binary vector fused to a β-glucuronidase (GUS) marker gene (pAsEXP1-GUS) and introduced into rice (Oryza sativa L.) callus ('Kassalatha'). Reverse transcription polymerase chain reaction confi rmed that the expression of pAsEXP1 in A. stolonifera was inducible by heat stress and exogenous applications of GA and ABA. Our results demonstrate that the AsEXP1 gene may be involved in the signal pathway of hormone regulation of plant responses to heat stress. © Crop Science Society of America.

Pan X.,Beijing Forestry University | Li H.,Beijing Forestry University | Wei H.,Beijing Forestry University | Su W.,Beijing Forestry University | And 5 more authors.
Molecular Biology Reports | Year: 2013

4-Coumarate:CoA ligase (4CL) is a key enzyme in the phenylpropanoid synthesis pathway. The Pto4CL2 promoter was cloned from Populus tomentosa Carr. and fused to the reporter gene encoding β-glucuronidase (GUS); the complex expression patterns directed by the Pto4CL2 promoter were then characterized in Nicotiana tabacum Xanthi by histochemical assays. The promoter 5′-deletion and histochemical assay conducted on transformants indicated that the -317 to -292 nt region supports Pto4CL2 expression in the epidermis and petals and the deletion of the -266 to -252 nt region resulted in the loss of tissue specificity and a dramatic reduction in GUS activity. Furthermore, electrophoretic mobility shift assays testified that an adenine and cytosine-rich element (-264 to -255 nt) and an abscisic acid-responsive element (-242 to -235 nt) in the Pto4CL2 promoter would have functions for the complex expression profiling and efficient basal expression, respectively. These results further clarify the mode of the regulatory expression of class II 4CL promoters in higher plants. © 2012 Springer Science+Business Media Dordrecht.

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