Expression of callose synthase genes and its connection with Npr1 signaling pathway during pathogen infection
Expression of callose synthase genes and its connection with Npr1 signaling pathway during pathogen infection
复制标题
DOI：
10.1007/s00425-008-0812-3
复制
发表时间：
2008-12-01
期刊：
影响因子：
4.3
通讯作者：
Verma, Desh Pal S.
中科院分区：
文献类型：
--
作者：
Dong, Xiaoyun;Hong, Zonglie;Verma, Desh Pal S.
胼胝质合成发生在所有细胞类型的植物细胞壁发育的特定阶段，是对病原体攻击、伤害和生理胁迫的反应。我们确定了12个拟南芥胼胝质合成酶基因（CalS1-12）“上游调控序列”的表达模式，证明了不同的胼胝质合成酶在植物发育的不同组织中有特异性表达。多个CalS基因在同一细胞类型中表达，表明CalS复合物可能是由异质亚基组成的。5个CalS基因被拟南芥透明operonospora arabidopsis（以前称为Peronospora parasitica，霜霉病的致病因子）或水杨酸（SA）诱导，其余7个CalS基因不受这些处理的影响。在诱导的基因中，CalS1和CalS12表现出最高的反应。在拟南芥npr1突变体中，发病相关基因（PR）对SA的反应受损，SA或病原体处理对CalS1和CalS12基因的诱导作用显著降低。在npr1突变体中，其他三个CalS基因的表达模式没有显著变化。这些结果表明，CalS1和CalS12的高诱导依赖于Npr1，而5个CalS基因的弱诱导则不依赖于Npr1。在CalS12的T-DNA敲除突变体中，受感染叶片吸器周围的胼胝质包膜减少，与野生型植物相比，该突变体对霜霉病的抗性更强。
Callose synthesis occurs at specific stages of plant cell wall development in all cell types, and in response to pathogen attack, wounding and physiological stresses. We determined the expression pattern of "upstream regulatory sequence" of 12 Arabidopsis callose synthase genes (CalS1-12) genes and demonstrated that different callose synthases are expressed specifically in different tissues during plant development. That multiple CalS genes are expressed in the same cell type suggests the possibility that CalS complex may be constituted by heteromeric subunits. Five CalS genes were induced by pathogen (Hyaloperonospora arabidopsis, previously known as Peronospora parasitica, the causal agent of downy mildew) or salicylic acid (SA), while the other seven CalS genes were not affected by these treatments. Among the genes that are induced, CalS1 and CalS12 showed the highest responses. In Arabidopsis npr1 mutant, impaired in response of pathogenesis related (PR) genes to SA, the induction of CalS1 and CalS12 genes by the SA or pathogen treatments was significantly reduced. The patterns of expression of the other three CalS genes were not changed significantly in the npr1 mutant. These results suggest that the high induction observed of CalS1 and CalS12 is Npr1 dependent while the weak induction of five CalS genes is Npr1 independent. In a T-DNA knockout mutant of CalS12, callose encasement around the haustoria on the infected leaves was reduced and the mutant was found to be more resistant to downy mildew as compared to the wild type plants.