Genes associated with arsenite uptake and transport in rice plants (i.e., OsLsi1, OsLsi2, OsLsi3, OsLsi6 and OsABCC1) have been identified to date. However, their expression over time during the whole growth period of rice under arsenite stress conditions is still poorly understood. In this study, the dynamics of gene expression associated with arsenite transport and arsenic concentrations in different organs of rice were investigated to determine the critical period(s) of arsenite uptake and translocation regulated by gene expression during the whole growth period. The relative expression of OsLsi2 and OsLsi1 in the roots was upregulated and reached its highest value (2-∆∆Ct = 4.04 and 1.19, respectively) at the jointing stage (9 weeks after transplantation), in which the arsenic concentration in roots also was the highest at 144 mg/kg. A range from 45.1 to 61.2% of total arsenic accumulated in the roots during seedling to heading stages (3–16 weeks), which was mainly associated with the relatively high expression of OsABCC1 (1.50–7.68), resulting in arsenic located in the vacuoles of roots. Subsequently, the As translocation factor from root to shoot increased over time from heading to milky ripe (16–20 weeks), and 74.3% of the arsenic accumulated in shoots at the milk stage. Such an increase in arsenic accumulation in shoots was likely related to the findings that (i) OsABCC1 expression in roots was suppressed to 0.14–0.75 in 18–20 weeks; (ii) OsLsi3 and OsABCC1 expression in nodes I, II, and III was upregulated to 4.01–25.8 and 1.59–2.36, respectively, in 16–20 weeks; and (iii) OsLsi6 and OsABCC1 expression in leaves and husks was significantly upregulated to 2.03–5.26 at 18 weeks. The jointing stage is the key period for the expression of arsenite-transporting genes in roots, and the heading to milky ripe stages are the key period for the expression of arsenite-transporting genes in shoots, both of which should be considered for regulation during safe rice production in arsenic-contaminated paddy soil.

中文翻译：

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水稻整个生育期与砷吸收和转运相关的基因表达动态

迄今为止，已鉴定出与水稻植物中砷吸收和运输有关的基因（即，OsLsi1，OsLsi2，OsLsi3，OsLsi6和OsABCC1）。然而，在砷胁迫条件下，水稻在整个生长期中随时间的表达仍知之甚少。在这项研究中，研究了水稻不同器官中与砷转运和砷浓度相关的基因表达动态，以确定在整个生长期中受基因表达调节的砷吸收和转运的关键时期。在拔节期（移植后9周），根中OsLsi2和OsLsi1的相对表达上调并达到最高值（分别为2-Δ∆Ct = 4.04和1.19），其中根中的砷浓度也达到了最大值。最高为144 mg / kg。从幼苗到抽穗期（3–16周），根部累积的砷总量占总砷的45.1％至61.2％，这主要与OsABCC1的相对高表达（1.50–7.68）有关，导致砷位于液泡中根。随后，从根到芽的As转运因子从抽穗到乳状成熟（16-20周）随时间的推移而增加，并且在乳期，芽中积累的砷占74.3％。芽中砷积累的增加可能与以下发现有关：（i）根中OsABCC1的表达在18-20周内被抑制到0.14-0.75。（ii）在16-20周内，节点I，II和III中的OsLsi3和OsABCC1表达分别上调至4.01-25.8和1.59-2.36；（iii）OsLsi6和OsABCC1在叶子和果壳中的表达显着上调至2.03–5。18周时26。拔节期是根部表达砷转运蛋白的关键时期，而进入乳白色成熟阶段是芽中砷转运蛋白表达的关键时期，在安全期间应同时进行调节。受砷污染的稻田中的水稻生产。