生物土壤结皮铁代谢微生物组成及其功能基因对演替的响应

采用微生物宏基因组学微阵列GeoChip 5.0技术，选择腾格里沙漠东南缘沙坡头地区不同年代人工固沙植被区的生物土壤结皮（BSC）为对象，分析BSC演替过程中参与铁代谢的功能微生物组成及其功能基因变化特征，研究微生物铁代谢对BSC演替的响应及调控。结果表明：真菌参与铁吸收和转运过程，古菌参与铁转运和贮存过程，细菌则在铁代谢吸收、转运和贮存过程中均起主要调控作用。门水平上，BSC铁代谢功能微生物组成变化对演替的响应不敏感，BSC铁代谢微生物主要为变形菌门（Proteobacteria）。BSC铁代谢功能基因多样性的显著提高和三类铁代谢过程基因信号强度达到最高水平需要经过61 a的演替。调控BSC铁吸收过程的主要功能基因为亚铁氧化酶编码基因iro；调控原核生物铁转运过程的主要功能基因，为羟基苯甲酰丝氨酸铁外膜转运体编码基因cirA和Fe（Ⅱ）转运蛋白编码基因feoB，真菌铁转运过程主要依靠含铁细胞转运体和铁氧化酶高亲和力的作用；调控铁贮存过程的主要功能基因为固定相类核蛋白编码基因dps。在BSC演替阶段末期，上述铁代谢功能基因强度的显著增加促进了微生物的铁代谢潜能。干旱、半干旱荒漠生态系统植被恢复过程中微生物铁代谢潜能的恢复需要较长时间。

Iron metabolism microbial composition and functional genes response to succession of biological soil crust

Based on the microbial genomics microarray GeoChip 5.0 technology, the BSC of artificial sand-fixation vegetation in southern margin of Tengger desert was selected as the research object. Fungi participate in the iron uptake and transport processes of BSC, archaea participate in the iron transport and storage processes, while bacteria play dominant roles in all three processes of iron metabolism. The microbial species composition of iron metabolism function at phylum level did not respond significantly to succession, and the iron metabolism processes are mainly regulated by Proteobacteria. The functional gene intensities of iron metabolism to increase significantly and the three types of iron metabolism processes to reach the highest functional level should take 61 years. The main functional gene regulating BSC iron absorption process is ferrous oxidase protein encoding gene iro; the main functional gene regulating the iron transport process of prokaryote is ferric dihyroxybenzoylserine outer membrane transporter coding gene cirA and Fe transporter permease subunit coding gene feoB, the fungal iron transport process mainly relies on the high affinity of iron-containing cell transporters and ferric oxidase; the main functional gene regulating iron storage process is stationary phase nucleoid protein encoding gene dps. At the end of the BSC succession phase, the significant increase in the intensity of the aforementioned iron metabolism functional genes promoted the iron metabolism potential of the microorganisms. It was proved that the restoration of microbial iron metabolism potential in the process of vegetation restoration in arid and semi-arid desert ecosystems takes a long time.