拟南芥莲座叶片发育过程中P1基因的表达特性

Expression Characteristics of P1 Gene during Rosette Leaf Development of Arabidopsis thaliana

该实验对CDF1类似蛋白基因(P1)在拟南芥叶片发育不同阶段的定量PCR结果显示,P1基因在拟南芥叶片发育的所有时期均可表达,但在茎生叶和衰老叶中的表达水平明显高于成熟叶和幼叶。GUS报告基因表达的组织化学染色结果显示,P1启动子在拟南芥叶片中有较高的驱动活性;在营养生长阶段的幼苗和植株(4~5周)的所有叶片中均能检测到GUS表达,但在植株转入生殖生长阶段后(6周及以后),GUS表达主要集中在逐渐衰老的叶中,并随着叶片衰老程度加剧GUS染色程度也越深,这一结果与GUS荧光定量检测结果一致。通过分析P1基因启动子上可能存在的顺式调控元件,发现茉莉酸甲酯、热压、干旱和水杨酸等均能够引起叶片衰老调控元件的响应,证实P1的表达受到这些因素的调控。研究表明,P1在拟南芥莲座叶片中很可能参与了对上游衰老信号的响应,该研究结果为进一步探究P1在叶片衰老过程中的分子功能验证奠定了基础。

In this study, the expression of CELL GROWTH DEFECT FACTOR 1 （CDF1）-like protein encoding gene P1 was detected in different developmental stages of Arabidopsis thaliana leaves by realtime PCR. The results showed that P1 is expressed in all developmental stages of rosette leaves, but its expres- sion was the highest in senescent leaves. GUS staining showed that P1 promoter has high driven activity in leaves. In seedlings and the vegetative stage plants （4--5 weeks old）, GUS staining can be detected in all rosette leaves, but after the plants entered into reproductive stages （after 6 weeks old）, the rosette periph- eral leaves began to yellowing and GUS staining was centralized to the senescing leaves and increased with leaf senescence progress, but the stain in younger leaves was weaker. GUS fluorescent quantitative analy- ses further confirmed the staining results. By searching cis-acting elements in P1 promoter, the elements related to MeJA-responsiveness, heat stress responsiveness, drought-inducibility and salicylic acid respon- siveness which have been previously proved to induce leaf senescence reactions were found. These results indicate that P1asa membrane protein in leaves is possibly participate in the cell response to leaf senes- cence signals. This study lays a foundation for the molecular function verification of P1 during leaf senes-cence process in {uture.