Gene expression of ADP-glucose pyrophosphorylase and starch contents in rice cultured cells are cooperatively regulated by sucrose and ABA
Gene expression of ADP-glucose pyrophosphorylase and starch contents in rice cultured cells are cooperatively regulated by sucrose and ABA
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DOI：
10.1093/pcp/pci101
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发表时间：
2005-06-01
影响因子：
4.9
通讯作者：
Fujimura, T
中科院分区：
文献类型：
--
作者：
Akihiro, T;Mizuno, K;Fujimura, T
从水稻全长cDNA数据库中提取6个cDNA克隆，分别编码adp -葡萄糖焦磷酸化酶（AGPase）的2个小亚基和4个大亚基，克隆后命名为OsAPS1、OsAPS2、OsAPL1、OsAPL2、OsAPL3和OsAPL4。用基因特异性探针对6个基因的表达模式进行Northern blot分析。OsAPL3主要在种子发育中期表达，OsAPS1、OsAPL1和OsAPL2在种子发育后期表达。在水稻种子发育过程中，OsAPS2和OsAPL4组成型表达与淀粉积累密切相关。为了更准确地阐明糖和植物激素对AGPase基因表达的影响，采用水稻细胞培养系统。随着培养基中蔗糖和脱落酸（ABA）浓度的增加，OsAPL3转录物显著积累；而其他AGPase基因的转录本没有明显的积累。在相同的条件下，培养细胞中的淀粉含量也有所增加。有趣的是，单独使用ABA并不影响OsAPL3的基因表达和淀粉含量。综上所述，培养细胞中OsAPL3的表达水平和淀粉含量受蔗糖和ABA浓度变化的共同控制。
Six cDNA clones encoding two small subunits and four large subunits of ADP-glucose pyrophosphorylase (AGPase) were mined from the database of rice full-length cDNAs, cloned and subsequently named: OsAPS1, OsAPS2, OsAPL1, OsAPL2, OsAPL3 and OsAPL4. Expression patterns of the six genes were examined by Northern blot analysis with gene-specific probes. OsAPL3 was predominantly expressed in the middle phases of seed development, and OsAPS1, OsAPL1 and OsAPL2 were expressed later in seed development. OsAPS2 and OsAPL4 were constitutively expressed and these isoforms were coordinated with starch accumulation in the developing rice seed. In order to clarify the effect of sugars and plant hormones on AGPase gene expression more precisely, a rice cell culture system was used. OsAPL3 transcript significantly accumulated in response to increased levels of sucrose and abscisic acid (ABA) concentration in the medium; however, the transcripts of other AGPase genes did not show significant accumulation. Under identical conditions, starch contents in the cultured cells also increased. Interestingly, ABA alone did not affect the gene expression of OsAPL3 and starch content. Collectively, these results indicated that the expression level of OsAPL3 and starch content in the cultured cells were cooperatively controlled by alterations in the concentration of both sucrose and ABA.