低磷胁迫对太空诱变耐低磷柱花草酸性磷酸酶活性和磷效率的影响  

Effects of phosphorus deficiency on acid phosphatase activity and phosphorus efficiency in a low-phosphorus tolerant Stylosanthes mutant

作　　者：刘攀道[1] 郇恒福[1] 刘一明 刘国道[1] 白昌军[1] 陈志坚[1] LIU Pan-dao;HUAN Heng-fu;LIU Yi-ming;LIU Guo-dao;BAI Chang-jun;CHEN Zhi-jian(Institute of Tropical Crop Genetic Resources,Chinese Academy of Tropical Agriculture Sciences ＆ Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China,Ministry of Agriculture,Danzhou 571737,China)

机构地区：[1]中国热带农业科学院热带作物品种资源研究所,农业部华南作物基因资源与种质创制重点实验室,海南儋州571737

出　　处：《草业学报》2018年第8期78-85,共8页Acta Prataculturae Sinica

基　　金：国家自然科学基金(31701492;31672483); 国家牧草产业技术体系岗位科学家项目(CARS-35); 中国热带农业科学院基本科研业务费专项资金(1630032017082;1630032016010;1630032017045;1630032017032)资助

摘　　要：低磷胁迫是酸性土壤限制牧草生产的主要障碍因子之一。本课题组前期的研究中,通过太空诱变获得了一个耐低磷柱花草突变体TPRC2001-84,但其适应低磷胁迫的机制仍不清楚。以TPRC2001-84及其亲本热研2号(RY2)为试验材料,通过水培方法,比较正常供磷(+P,250μmol·L-1 KH2PO4)和低磷(-P,5μmol·L-1KH2PO4)处理对TPRC2001-84和RY2生物量、磷吸收效率、磷利用效率、可溶性磷浓度、细胞壁磷含量和酸性磷酸酶(ACP)活性的影响。结果表明,相对于正常供磷处理,低磷处理显著降低了两份柱花草材料的植株干重和磷吸收效率(P<0.05),但显著提高了两份柱花草材料的磷利用效率(P<0.05)。并且,TPRC2001-84在低磷处理下的植株干重和磷利用效率分别是RY2的1.6和1.4倍。在低磷胁迫下,虽然TPRC2001-84叶片和根系的细胞壁磷含量只有RY2的70%左右,但是,TPRC2001-84叶片和根系的可溶性磷浓度分别比RY2高36.8%~42.6%,细胞壁ACP活性分别比RY2高46.6%~53.6%。以上结果说明,柱花草TPRC2001-84在低磷胁迫下具有较高的细胞壁ACP活性,有利于其对细胞壁中贮存磷的活化利用,从而获得较高的磷利用效率。这将为选育磷高效柱花草新品种提供理论依据和种质材料。Low phosphorus （P） availability is a major constraint for pasture yields in acid soils. In a previous study, a low-P tolerant stylo （ Stylosanthes ） mutant, TPRC2001-84, was created using space flight mutation. However, the underlying mechanisms of TPRC2001-84 tolerance of P deficiency remain largely unknown. In this study, plant biomass, P acquisition efficiency, P utilization efficiency, soluble inorganic phosphate （Pi） concentration, cell wall P content and acid phosphatase （ACP） activity were investigated in hydroponically grown TPRC2001-84 and a non-mutant control （RY2） in normal P （＋P, 250 μmol·L -1 KH 2PO 4） or low P （-P, 5 μmol·L -1 KH 2PO 4） solutions. Plant dry weight and P acquisition efficiency were significantly decreased （ P 〈0.05） by P deficiency, while P utilization efficiency was increased （ P 〈0.05） by low P in both accessions, compared to the normal P treatment. Plant dry weight and P utilization efficiency of TPRC2001-84 were 1.6 and 1.4 times those of RY2 under P deficiency, respectively. Although cell wall P content in leaves and roots of TPRC2001-84 were about 70% lower than in RY2 with low P treatment, the soluble Pi concentration in leaves and roots of TPRC2001-84 were 36.8% and 42.6% higher than in RY2 under P deficiency, respectively. Similarly, cell wall ACP activity in leaves and roots of TPRC2001-84 were 46.6% and 53.6% higher than in RY2 under P deficiency, respectively. These results suggest that increased cell wall ACP activity in TPRC2001-84 may contribute to cell wall P scavenging and recycling, increasing P utilization efficiency under P deficiency. Taken together, our results provide a theoretical basis and germplasm resource for selecting and breeding stylo varieties with high P efficiency.

关 键 词：柱花草 低磷胁迫 酸性磷酸酶 磷效率 太空诱变 

分 类 号：S541.9[农业科学—作物学]