外源硫化氢对盐碱胁迫下裸燕麦矿质元素吸收、运输和分配的影响

Effect of Exogenous Hydrogen Sulfide on the Absorption,Transportation and Distribution of Mineral Elements in Naked Oats under Saline-Alkali Stress

为了解硫化氢(H_(2)S)对盐碱胁迫下裸燕麦矿质元素吸收、运输和分配的调控效应,以裸燕麦品种定莜9号为材料,采用盆栽砂培试验,研究抽穗期喷施50μmol·L^(-1)H_(2)S供体硫氢化钠(NaHS)溶液对50 mmol·L^(-1)盐碱混合胁迫下裸燕麦根、茎和叶中29种矿质元素和4种阴离子含量及矿质元素选择性运输、质膜Na^(+)/H^(+)逆向转运蛋白基因SOS1和液泡膜Na^(+)/H^(+)逆向转运蛋白基因NHX1表达和植株生物量的影响。结果表明,在裸燕麦根、茎和叶中未检出硒元素和CO_(3)^(2-)。盐碱胁迫下,外源H_(2)S对裸燕麦效应:(1)对根、茎和叶中HCO_(3)^(-)、Cl^(-)和SO_(4)^(2-)含量无显著影响,可显著缓解盐碱胁迫下裸燕麦根系和地上部干重的下降;(2)显著降低茎、叶中Na含量,对根中Na含量和叶片SOS1基因表达无显著影响,显著提高叶片NHX1基因表达量;(3)提高根、茎和叶中Ca、Mg、P的含量,抑制K的吸收和运输;促进S的吸收,但抑制S的转运;降低根、茎中Si含量,通过提高Si从茎向叶转运而提高叶中Si含量;(4)显著提高根、茎和叶中Co含量;促进Ni的转运及Fe从根向茎、Zn从茎向叶的转运,提高根中Mn、Zn和茎中Fe及叶片Ni、Zn含量;抑制B、Mn、Cu、Zn从根向茎和Mo从茎向叶的转运,降低茎中B、Mn、Cu、Ni、Zn和叶片中B、Mn、Cu、Mo含量;(5)显著提高根中Li、Sr、Ag和茎中Li、Sr及叶片Sr、Ag含量,降低根中Ba和叶片Rb含量;(6)对根、茎和叶中重金属元素Cd、Hg、Pb、Cr和As含量的影响存在差异,对根、茎和叶中Al含量的升高有显著缓解作用。由此可见,外源H_(2)S参与盐碱胁迫下裸燕麦矿质元素吸收、转运和分配的调控,能够增强裸燕麦的耐盐碱性。

The regulatory effects of hydrogen sulfide(H,S)on the absorption,transportation and distribution of mineral elements in naked oats under saline-alkali stress were studied.A potted sand culture experiment was conducted using the naked oat cultivar Dingyou 9 as experimental material and the effects of spraying 50μmol·L^(-1)H_(2)S donor sodium hydrosulfide(NaHS)solution at the heading stage on the contents of 29 mineral elements and 4 anions in the roots,stems and leaves,the selective transport of mineral elements,and the expression levels of plasma membrane Na^(+)/H^(+)antiporter gene SOS1 and vacuolar Na^(+)/H^(+)exchanger gene NHX1,as well as plant growth under 50 mmol·L^(-1)saline-alkali stress were investigated.The results showed that selenium and CO_(3)^(2-)were not detected in roots,stems and leaves of naked oats.Exogenous H_(2)S had no significant effect on the contents of HCO_(3)^(-),Cl^(-)and SO_(4)^(2-)in roots,stems and leaves of naked oats under saline-alkali stress,but it significantly alleviated the decrease in dry weight of roots and shoots of naked oats under saline-alkali stress.Under saline-alkali stress,exogenous H_(2)S significantly reduced sodium content in stems and leaves of naked oats;yet it had no significant effect on Na content in roots and the expression of SOS1 gene in leaves,while significantly increased the expression of NHX1 gene in leaves.Exogenous H_(2)S increased the content of calcium,magnesium,and phosphorus in roots,stems and leaves of naked oats under saline-alkali stress,inhibited the absorption and transport of potassium,promoted the absorption of sulfur and inhibited the transport of sulfur,decreased the content of silicon(Si)in roots and stems but increased the transport of Si from stems to leaves and increased the content of Si in leaves.Exogenous H_(2)S significantly increased cobalt content in roots,stems and leaves of naked oats under saline-alkali stress,promoted the transfer of nickel(Ni),the transfer of iron(Fe)from roots to stems,and zinc(Zn)from stems to leaves,increased the content of manganese(Mn)and Zn in roots,Fe in stems,and Ni and Zn in leaves,while inhibited the transport of boron(B),Mn,copper(Cu),Zn from roots to stems and molybdenum(Mo)from stems to leaves,but reduced the content of B,Mn,Cu,Ni and Zn in stems and B,Mn,Cu,and Mo in leaves.Exogenous H,S significantly increased the content of lithium(Li),strontium(Sr)and silver(Ag)in roots,Li and Sr in stems,and Sr and Ag in leaves of naked oats under saline-alkali stress,while reduced the content of barium in roots and rubidium in leaves.Exogenous H_(2)S had different effects on the heavy metal element cadmium,mercury,lead,chromium and arsenic in roots,stems and leaves of naked oats under normal conditions and saline-alkali stress,and it has a significant alleviating effect on the increase of aluminum content in roots,stems and leaves of naked oats under saline-alkali stress.Therefore,exogenous H_(2)S participated in the regulation of absorption,transportation and distribution of mineral elements in naked oats under saline-alkali stress,and it enhanced the saline-alkali tolerance of naked oats.