植物生态学报

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伯克霍尔德菌通过改善生理适应性及调节铝响应基因的表达增强甘蔗对铝胁迫的耐受性

陆珍1,谢光杰2,Qaisar Khan3,覃英4,黄毓燕4,郭道君5,杨婷婷6,杨丽涛2,邢永秀2,李杨瑞7,王震8   

  1. 1. 广西壮族自治区农业科学院
    2. 广西大学
    3. 丽水学院生态学院
    4. 广西大学农学院
    5. 河西学院
    6. 广西外国语学院
    7. 广西农业科学院
    8. 玉林师范学院智慧农业学院
  • 收稿日期:2024-01-19 修回日期:2024-10-21 发布日期:2025-01-20
  • 通讯作者: 李杨瑞

Burkholderia enhances the tolerance of sugarcane to aluminum stress by improving physiological adaptability and regulating the expression of aluminum responsive genes

Zhen LU1,TA QUANGKIET2,Khan Qaisar3,英 覃4,毓燕 黄4,道君 郭5,婷婷 杨6,Yang LiTao2,Xing YongXiu2,Li YangRuiZhen WANG8   

  • Received:2024-01-19 Revised:2024-10-21
  • Contact: Li YangRui

摘要: 摘 要 多种因素可影响植物生长并提高其抗逆性, 其中植物根际促生菌(PGPR)可能扮演着极其重要的角色。为挖掘耐铝性良好的根际微生物资源并探讨其缓解甘蔗(Saccharum officinarum)铝毒害的作用, 该研究从甘蔗根际土壤中分离出一批耐铝细菌, 分析它们的促生特性、耐酸性、耐铝性以及对Al3+的去除能力, 筛选出优势PGPR并检测其对甘蔗的促生长效应, 对比接种和不接种PGPR的甘蔗在铝胁迫下植株体内的铝积累量、生理代谢情况以及耐铝相关基因的表达量。分离筛选到的3株优势甘蔗根际细菌——伯克霍尔德菌(Burkholderia) A1、A23、X6具有较强的耐酸性(pH?3.8)和耐铝性(4或5 mmol·L–1), 3株细菌均具有溶磷、分泌胞外聚合物(EPS)、固氮和去除Al3+的能力, X6能够产生少量吲哚乙酸, A1和X6可分泌较多的铁载体, A23和X6具有1-氨基环丙烷-1-羧酸脱氨酶活性, A1、A23、X6菌株组合可显著提高甘蔗株高、叶面积及地上部分鲜质量。接种组合菌对植株地上部分与地下部分氮、磷、钾的含量无明显影响, 但显著增加了0.5、1 mmol·L–1铝胁迫下甘蔗地上部分的铝含量和显著降低了1 mmol·L–1铝胁迫下甘蔗地下部分的铝含量, 总体表现为降低甘蔗体内的总铝含量。接种处理对植株超氧化物歧化酶、过氧化物酶活性以及脯氨酸、可溶性蛋白含量无显著影响, 但显著降低了铝胁迫下甘蔗根尖的丙二醛含量和显著提高了根尖的过氧化氢酶活性, 显著增加了甘蔗根尖MAPK和GST基因以及叶片PEPC基因的表达量。这些结果表明, 耐铝伯克霍尔德菌对甘蔗生长、铝的吸收积累和植株抗氧化防御能力及耐铝基因表达产生显著影响, 这些影响共同作用提高了甘蔗的耐铝毒能力。

关键词: 伯克霍尔德菌, 甘蔗, 铝胁迫, 生理适应性, 耐铝基因

Abstract: Abstract Aims Many factors can influence the growth of plants and their adaptability to the growing environment, among which plant growth promoting rhizobacteria (PGPR) may play a key role. Thus, the aim of this study is to explore the rhizosphere microbial resources with good aluminum tolerance and investigate their role in alleviating aluminum toxicity of sugarcane. Methods We isolated and screened the dominant strains of aluminum-tolerant PGPR from the rhizosphere soil of sugarcane (Saccharum officinarum) and studied their effects on sugarcane growth. By measuring the aluminum accumulation, physiological metabolism and expression changes of aluminum-tolerant genes in the aboveground and underground parts of sugarcane after aluminum stress, we compared the aluminum tolerance of sugarcane inoculated with aluminum-tolerant bacteria and those without aluminum-tolerant bacteria. Important findings Three strains of dominant sugarcane rhizosphere bacteria, Burkholderia A1, A23 and X6, have strong acid resistance (pH 3.8) and aluminum tolerance (4 or 5 mmol·L–1). All the three strains have the ability to dissolve phosphorus, secrete extracellular polymeric substances (EPS), fix nitrogen and remove Al3+. X6 can produce low level indole-3-acetic acid (IAA), A1 and X6 can secrete more iron carriers, and A23 and X6 have aminocyclopropane-l-carboxylic acid (ACC) deaminase activity. The combined bacteria of A1, A23 and X6 improved the plant height, leaf area and fresh weight of aboveground part of sugarcane. Although the bacteria combinations showed no obvious effect on the contents of nitrogen, phosphorus and potassium in aboveground and underground parts of the plant, but significantly increased the aluminum content in aboveground part of sugarcane under 0.5 and 1 mmol·L–1 aluminum stress and significantly reduced the aluminum content in underground part of sugarcane under 1 mmol·L–1 aluminum stress, and the overall performance was reducing the total aluminum content in sugarcane. The inoculation treatment showed no significant effect on the activities of superoxide dismutase (SOD) and peroxidase (POD), and the contents of proline (Pro) and soluble protein (SP), but it significantly reduced the malondialdehyde (MDA) content and significantly increased the catalase (CAT) activity in root tips under aluminum stress, and significantly increased the expression of MAPK and GST genes in root tips and PEPC gene in leaves of sugarcane. These results showed that Al-tolerant Burkholderia had significant effects on sugarcane growth, aluminum absorption and accumulation, plant antioxidant defense ability and aluminum-tolerant gene expression, which together improved the aluminum tolerance of sugarcane.

Key words: Burkholderia, Saccharum officinarum, aluminum stress, physiological?adaptation, aluminum resistance genes