Guo Dao-Jun, Singh Rajesh Kumar, Singh Pratiksha, Li Dong-Ping, Sharma Anjney, Xing Yong-Xiu, Song Xiu-Peng, Yang Li-Tao, Li Yang-Rui
College of Agriculture, Guangxi University, Nanning, China.
Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture, Sugarcane Research Center, Chinese Academy of Agricultural Sciences, Nanning, China.
Front Microbiol. 2020 Sep 22;11:580081. doi: 10.3389/fmicb.2020.580081. eCollection 2020.
Sugarcane is the leading economic crop in China, requires huge quantities of nitrogen in the preliminary plant growth stages. However, the use of an enormous amount of nitrogen fertilizer increases the production price, and have detrimental results on the environment, causes severe soil and water pollution. In this study, a total of 175 endophytic strains were obtained from the sugarcane roots, belonging to five different species, i.e., , , , , and . Among these, only 23 strains were chosen based on nitrogen fixation, PGP traits, hydrolytic enzymes production, and antifungal activities. Also, all selected strains were showed diverse growth range under different stress conditions, i.e., pH (5-10), temperature (20-45°C), and NaCl (7-12%) and 14 strains confirmed positive , and 12 strains for gene amplification, suggested that these strains could fix nitrogen along with stress tolerance properties. Out of 23 selected strains, ED5 was the most potent strain. Hence, this strain was further selected for comprehensive genome analysis, which includes a genome size of 4,702,851 bp and 56.05% of the average G + C content. Genome annotations estimated 4349 protein-coding with 83 tRNA and 25 rRNA genes. The CDSs number allocated to the KEGG, COG, and GO database were 2839, 4028, and 2949. We recognized a total set of genes that are possibly concerned with ACC deaminase activity, siderophores and plant hormones production, nitrogen and phosphate metabolism, symbiosis, root colonization, biofilm formation, sulfur assimilation and metabolism, along with resistance response toward a range of biotic and abiotic stresses. ED5 strain was also a proficient colonizer in sugarcane (variety GT11) and enhanced growth of sugarcane under the greenhouse. To the best of our knowledge, this is the first information on the whole-genome sequence study of endophytic ED5 bacterium associated with sugarcane root. And, our findings proposed that identification of predicted genes and metabolic pathways might describe this strain an eco-friendly bioresource to promote sugarcane growth by several mechanisms of actions under multi-stresses.
甘蔗是中国主要的经济作物,在植株生长初期需要大量氮素。然而,大量使用氮肥会增加生产成本,并对环境产生不利影响,导致严重的土壤和水污染。在本研究中,从甘蔗根部分离得到175株内生菌株,分属于5个不同物种,即 、 、 、 和 。其中,基于固氮、植物促生特性、水解酶产生和抗真菌活性,仅挑选出23株菌株。此外,所有挑选出的菌株在不同胁迫条件下,即pH(5 - 10)、温度(20 - 45°C)和NaCl(7 - 12%)下均表现出不同的生长范围,14株菌株 检测呈阳性,12株菌株 基因扩增呈阳性,表明这些菌株具有固氮能力以及胁迫耐受特性。在23株挑选出的菌株中,ED5是最具潜力的菌株。因此,进一步挑选该菌株进行全基因组分析,其基因组大小为4,702,851 bp,平均G + C含量为56.05%。基因组注释估计有4349个蛋白质编码基因,83个tRNA基因和25个rRNA基因。分配到KEGG、COG和GO数据库的CDS数量分别为2839、4028和2949。我们识别出了一组可能与ACC脱氨酶活性、铁载体和植物激素产生、氮和磷代谢、共生、根定殖、生物膜形成、硫同化和代谢以及对一系列生物和非生物胁迫的抗性反应相关的基因。ED5菌株也是甘蔗(品种GT11)中的高效定殖菌,并在温室条件下促进了甘蔗的生长。据我们所知,这是关于与甘蔗根相关的内生ED5细菌全基因组序列研究的首次信息。而且,我们的研究结果表明,对预测基因和代谢途径的鉴定可能表明该菌株是一种生态友好型生物资源,可通过多种作用机制在多重胁迫下促进甘蔗生长。