胡萝卜HRGP启动子调控GUS基因的某些特点

HRG(hydroxyproline rich glycoproteins)是高等植物细胞壁中一类富含羟脯氨酸的糖蛋白,是植物细胞壁中主要的结构蛋白。早期研究认为其在细胞壁的形成过程中起作用并称之为伸展蛋白(extensin)。在双子叶植物中,HRGP基因以多基因家族形式存在,具有特定的表达模式。许多条件及处理都能引起HRGP表达量的增加,如伤害、真菌感染、病毒感染、乙烯、细胞培养、红光等,同时也受到发育水平的调节。在单子叶植物中,玉米HRGP的表达是在发育水平上受伤害调节的。HRGP基因还具有组织专一性表达的特点。在大豆种子中,HRGP主要存在于种皮的外两层、表皮栅栏组织和滴漏细胞中,属于起支持作用的厚壁组织。在胡萝卜根韧皮部薄壁细胞中HRGP含量最丰富,而在健康的番茄根中

GUS ACTIVITIES UNDER CONTROL OF HRGP PROMOTER OF CARROT

Hydroxyproline rich glycoprotein (HRGP) promoter has been cloned from genomic clone of carrot (Daucus carota var. sativa DC.) by PCR procedure. The construction with fusion gene of carrot HRGP/GUS in binary vector were used for the genetic transformation by Agrobacteriwn mediated procedure and the transgenic tobaccoes with this transgene were obtained. The GUS activities in various organs have been studied by histochemical examination. Tissue specific activities of this HRGP promoter were demonstrated. GUS activities were expressed in the apical meristematic zones of roots, inner phloem of stems, inner and outer phloem of petioles. The highest levels of GUS activity were found in tissues where axillary bud was initiated. The expression of GUS activities under the control of carrot HRGP promoter could also be enhanced by treatment with the inducing factors such as salicylic acid, CaCl2 and NaCl.