Analysis of GLP (germin-like protein) genes related to photoperiodic response

ppglp （Pharbitis nil gemin-like protein）是一种在短日照植物（php . nil cv.）的叶片和子叶中积累的基因。紫色在花诱导的黑暗期，编码GLP基因叶型亚家族的成员。GLP蛋白的功能大部分是未知的。Northern分析显示，pglp mRNA水平具有昼夜节律性，在暗期开始后10小时左右达到峰值，这种振荡在延长的连续黑暗中持续。AtGLP1和AtGLP2 mRNA在Aratidcpsis叶片中的积累也具有昼夜节律性，在光照开始后14 h左右达到最大值。这些振荡主要在连续光照下持续。AtGLP1和AtGLP2的调控模式与pglp相反，可能反映了短日照植物与长日照植物的差异。为了研究叶片型GLP gsne调控与光周期相关的分子机制，我们决定以荧光素酶基因作为报告基因分析这些基因的启动子区域。由于在这些染色体中没有保守的顺式元件，我们目前正在分析一系列启动子缺失结构，以确定哪些序列基序对昼夜节律表达至关重要。目的：确定pglp对光周期诱导开花的影响。我们目前正在研究表达pglp cDNA的天源植物。以短日照烟草（Nicotiona tabacum cv.）为试验材料。与对照植物相比，表达pglp cDNA的烟草植株更容易形成花穗。表达pglp cDNA的烟草植株可能是短日照植物光周期诱导开花的温和刺激物。我们的实验目前正在进行中。

PnGLP (Pharbitis nil gemin-like protein) is a gene whose transcript is accumulated in leaves and cotyledons of the very sensitive short-day plant, P. nil cv. Violet during the flower-inductive dark-period and encodes a member of the leaf-type subfamily of GLP genes. The functions of GLP proteins are mostly unkown. Northern analysis revealed that the level of PnGLP mRNA showed a circadian rhythm, with maxima around 10 h after the beginning of the dark period, and this oscillation continued in lengthened continuous daikness. Homologues of PnGLP in Aratidcpsis (along-day plait), namely, AtGLP1 and AtGLP2 were isolated and characterized Accumulation of AtGLP1 and AtGLP2 mRNA in leafalso showed circadian rhythms, with maxima around 14 h after the beginning of the light period. These oscillaticns continued mostly under continuous light. The mode of regulation in AtGLP1 and AtGLP2 showed opposite to that of PnGLP, possibly reflecting the differences between short-day plants and long-day plants. To study the mdecularmechanisms ofleaf-type GLP gsne regulation in relati on to photoperiodism, we decided to analyze promoter region ofthese genes using a luciferase gene as a reporter. Because there were no conserved cis-lements among these ptomoteis, we are currently analyzing a series of promoter deletion constructs to identify which sequence motif is essential for circadian rhythmic expression. To deteimine the effects of PnGLP to photoperiodic induction of flowering. we are cumently studying tiansgenic plants expressing PnGLP cDNA. We used short-day tobacco plant (Nicotiona tabacum cv. Maryland Mammoth) as a host plant Tobacco plants that express PnGLP cDNA were likely to form flower earHerwhen they compared to control plant. Tobacco plants that express PnGLP cDNA were likely to from works as a mild stimulator for photoperiodic induction of flowering in short-day plants. Our experiment is currently underway on such hypothesis.