The Role of Phytochrome in Photoperiodic Timing Mechanisms(Physiology and Biochemistry of Flowering, For Further Development of Horticulture in East Asia)

スポンサーリンク

概要

• 論文の詳細を見る

• For over 50 years it has been known that the chromoprotein phytochrome has a fundamental role in photoperiodic timing mechanisms. However, exactly how phytochrome is involved in measuring the length of the dark period has eluded all attempts by researchers to elucidate biochemical and molecular mechanisms. This predicament can be partly explained by the recent discovery that phytochrome is actually a family of a number of related photoreceptors with separate, but overlapping functions. We have been engaged in an attempt to delineate the roles of individual phytochromes in photoperiodic timing in both a LDP and a SDP through reverse genetics. We are using transgenic plants of Nicotiana sylvestris (a LDP) and Nicotiana tabacum cv. Maryland Mammoth (a SDP) that have been engineered to overproduce or underproduce either Phy A or Phy B using a double 35S promoter to enhance expression of the transgenes. To date three homozygous antisense tobacco PHYA lines of N. sylvestris have been obtained ; PCR analysis showed the integration of the transgene, and these lines displayed longer hypocotyls under continuous far red light. A total of five N. sylvestris lines expressing PHYB in the sense orientation have also been identified by PCR analysis. Seedlings of four of these putative PHYB overexpressing lines had significantly shorter hypocotyl lengths under continuous red light. Interestingly, one overexpressing PHYB line exhibited a phenotype consistent with co-suppression : under red light, hypocotyls of this line were much longer than those of wild type seedlings. We are now in the process of examining the photoperiodic responses in both classes of transgnic plants. We are also in the process of characterizing plants of N. sylvestris transformed with PHYB in the antisense orientation, as well as N. tobacum cv. Maryland Mammoth plants transformed with PHYB in both the sense and antisense orientation, and with PHYA in the antisense orientation. Further progress on the molecular characterization of these additional transgenic lines is reported.

• 園芸学会の論文
• 1998-11-15

著者

• ZHENG Z.

  Department of Orthopaedic Surgery, Sun-Yat Sen University Medical College

• Metzger James

  Department Of Horticulture And Crop Science The Ohio State University

• Zheng Z.

  Department Of Horticulture And Crop Science The Ohio State University

• Zheng Z.-L.

  Department of Horticulture and Crop Science, The Ohio State University

関連論文

• Vertebroplasty by Use of a Strontium-Containing Bioactive Bone Cement
• The Role of Phytochrome in Photoperiodic Timing Mechanisms(Physiology and Biochemistry of Flowering, For Further Development of Horticulture in East Asia)

スポンサーリンク