Dark Signaling in Photoperiodic Induction of Flowering

开花光周期诱导中的暗信号

• 批准号: 9317249
• 负责人: Sharman O'Neill
• 金额: $ 30万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-01-15 至 1997-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9317249&HistoricalAwards=false
• 关键词: Dark; Signaling; Photoperiodic; Induction; Flowering

9317249 O'Neill Flowering involves the developmental transition of the shoot meristem from vegetative to reproductive growth. In many species of flowering plants, this developmental transition is regulated by photoperiod. The principal site of photoperiodic perception is the leaf, where inductive processes are proposed to lead to the synthesis of a floral stimulus that is translocated to target cells of the apical meristem where floral evocation is triggered. This process therefore involves interorgan signaling mediated by a translocatable chemical messenger of darkness. The biochemical and molecular basis of photoperiodic perception and signal transduction to the apex, however, remains a major unsolved problem in plant development. Recently, Dr. O'Neill has identified N-acetyl 5-methoxytryptamine, or melatonin, in several photoperiodic plant species and has determined that the concentration of this methoxylated indoleamine in the photoreceptive tissue of Pharbitis nil is correlated with dark induction of flowering. Melatonin is a well-known hormone involved in the regulation of seasonal reproduction in many diverse eukaryotic taxa including vertebrates, insects, and algae where it functions as a chemical messenger of "darkness". The detection of melatonin in plants, and the rhythmic cycling of its concentration, suggest the possibility that melatonin may also be an important biochemical component of photoperiodic signal transduction in plants. In related research, Dr. O'Neill has also characterized a set of mRNAs whose abundance cycles in parallel with photoperiodic floral induction. These results suggest that photoperiodic responses in the leaf may be mediated by activation of gene expression. *** 9 : $ ; \ = , ? Õ @ b A B C Z l H T I S K I O \ b X EU V F F t ^ & ? t + q v$ v" F P F P F V u L v$ v" F" V$ F F u N ^ ^ F & t~ v & D 9317249 O'Neill Flowering involves the developmental transition of the shoot meristem from vegetative to reproductive growth P K P ! ! F ! P P ( Times New Roman Symbol & Arial N " h d `B e^B e V + Dana Brigham Dana Brigham

9317249 O'Neill开花涉及茎部分生组织从营养生长到生殖生长的发育转变。在许多开花植物中，这种发育转变受光周期的调节。光周期感知的主要部位是叶片，在叶片中，诱导过程导致花刺激的合成，该刺激被转运到顶端分生组织的靶细胞，在那里触发花的召唤。因此，这一过程涉及到由可易位的黑暗化学信使介导的器官间信号。然而，光周期感知和信号转导的生物化学和分子基础仍然是植物发育中尚未解决的主要问题。最近，O'Neill博士在几种光周期植物物种中发现了n -乙酰基5-甲氧基色胺或褪黑激素，并确定了这种甲氧基吲哚胺在光感受组织中的浓度与黑暗诱导开花有关。褪黑素是一种众所周知的激素，在许多真核生物分类群中，包括脊椎动物、昆虫和藻类，它作为“黑暗”的化学信使参与调节季节性繁殖。植物中褪黑激素的检测及其浓度的节律性循环表明，褪黑激素也可能是植物光周期信号转导的重要生化成分。在相关研究中，O’neill博士还描述了一组mrna，其丰度周期与光周期花诱导平行。这些结果表明，叶片的光周期反应可能是通过激活基因表达来介导的。*** 9: $；\ =, ？Õ @ b A b C Z 1 H T I S K I O \ b X EU V F F T ^ & ？t + q v$ v" F P P P F v u L v$ v" F" v$ F F u N ^ ^ F & &; t~ v & D O'Neill开花涉及到茎部分生组织从营养生长到生殖生长的发育转变K P!!F !P (Times New Roman Symbol & Arial N " h d ' B e^B e V + Dana Brigham) Dana Brigham