Analysis of transporters and transcription factors controlling suberization in Casparian strip in rice

在水稻中，根外部的皮下组织形成一层纤维化的细胞壁(卡氏条带和/或板层)，这抑制了水分和离子的流动。我们研究了ABC转运蛋白RCN1是否参与了Casparian条带和Suberin片层的形成，并试图通过鉴定控制Suberin生物合成基因和Suberin转运蛋白基因表达的转录因子来了解Casparian条带和Suberin片层中Suber化的机制。在停滞的缺氧条件下，野生型的皮下组织发育良好，而rcn1突变体则不发育。在野生型中，质外体示踪剂高碘酸被阻止在皮下，而在rcn1中则没有，这表明突变体的质外体屏障受到了损害。此外，我们还鉴定了一些可能控制Casparian条带和Suberin片层形成的转录因子。

In rice, the hypodermis in the outer part of roots forms a suberized cell wall (Casparian strip and/or suberin lamellae), which inhibits the flow of water and ions. We examined if an ABC transporter RCN1 is involved in the Casparian strip and suberin lamellae formations and tried to understand the mechanism of suberization in Casparian strip and suberin lamellae by identifying transcription factors, which control expressions of suberin biosynthetic genes and suberin transporter genes. Under stagnant deoxygenated conditions, well-suberized hypodermis developed in the wild type but not in the rcn1 mutant. An apoplastic tracer, periodic acid, was blocked at the hypodermis in the wild type but not in rcn1, indicating that the apoplastic barrier in the mutant was impaired. Moreover, we identified some transcription factors, which might control the formations of Casparian strip and suberin lamellae.