水稻钾素营养的基因型特征及分子机制初探  

Genotypic Characteristics and Molecular Mechanism of Potassium Nutrition in Rice

作　　者：赵鹏姝 杨顺瑛[1] 郝东利[1] 苏彦华[1] ZHAO Pengshu;YANG Shunying;HAO Dongli;SU Yanhua(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008 [2]中国科学院大学,北京100049

出　　处：《土壤》2021年第1期37-46,共10页Soils

基　　金：国家自然科学基金项目(31672230)资助。

摘　　要：理解水稻(Oryza sativa)的钾素营养特征是提高水稻的钾素利用效率及其生产效应的重要环节。本文针对土壤钾素供应的时空非均匀性,采用水培和分根模拟试验,研究了日本晴(NB)、武育粳18(WYJ18)、南光(NG)及桂单4号(GD4)4个水稻基因型品种的钾素营养特征。结果表明:低钾(0.1 mmol/L K^(+))或高钾(5 mmol/L K^(+))条件均会显著抑制水稻的生长。与高钾条件相比,NB和GD4在低钾及正常供钾(1 mmol/L K^(+))水平下即可保持较高的生物量,推测NB和GD4有更强的钾吸收及转运能力。分根供钾试验表明,4种基因型水稻缺钾一侧的根长和根表面积均受到诱导,而地上部生物量与全根供钾时没有明显差异,说明局部根系供钾即可满足水稻生长需求。进而以NB为材料,通过实时荧光定量PCR,发现水稻根内钾转运基因OsKAT1;1主要定位于根部,且受高钾和低钾抑制,地上部钾分配基因OsAKT2/3主要定位于地上部且受高钾诱导,根–茎钾传输系统OsSKOR基因主要定位于距根尖大于1.5 cm的成熟区,且在根部的表达丰度受低钾诱导;水稻伤流试验结果表明,低钾条件下伤流液的强度和组分与根–茎传输基因OsSKOR的表达特征有较好的吻合度,推测OsSKOR基因可能在根–茎钾转运过程中发挥重要作用。Understanding potassium nutrition characteristics of rice is an important step to improve the potassium utilization efficiency and production effect of rice.Aims at the temporal and spatial heterogeneity of soil potassium supply,in this study,Nipponbare(NB),Wuyujing 18(WYJ18),Nanguang(NG)and Guidan 4(GD4)four genotypes of rice were used to evaluate the potassium response characteristics by using hydroponic and root division simulation tests.The results showed that insufficient potassium(0.1 mmol/L K^(+))or excess(5 mmol/L K^(+))significantly inhibited rice growth.NB and GD4 maintained high biomass under low and normal potassium(1 mmol/L K^(+))supply levels compared with high potassium conditions,possibly attributed to the stronger potassium absorption and transport capacity of NB and GD4.Root division experiment simulated the uneven distribution of potassium showed root lengths and surface areas of the four genotypes were induced on potassium-deficient side,but no significant difference was found between the aboveground biomass compared with the total root potassium supply,indicating the partial potassium supply also can meet the growth requirements of rice.NB was used to study the expression position by using real-time quantitative PCR,and it was found that potassium transport gene OsKAT1;1 in rice roots is mainly located in the roots and inhibited by high and low potassium.The above-ground potassium distribution gene OsAKT2/3 is mainly located in the shoots and induced by high potassium.The root-stem potassium transport system OsSKOR is mainly located in a mature region with a root tip greater than 1.5 cm,and the expression abundance at the root was induced by low potassium.The result of rice injury test showed that the strength and composition of the wound fluid had a good agreement with the expression of root-stem transfer gene OsSKOR under low potassium condition,suggesting OsSKOR may play an important role in root-stem potassium transport.

关 键 词：水稻 钾 生理响应 钾转运 分子机制 

分 类 号：Q786[生物学—分子生物学] Q945.1