Endophytic bacteria in sunflower (Helianthus annuus L.):: isolation, characterization, and production of jasmonates and abscisic acid in culture medium
Endophytic bacteria in sunflower (Helianthus annuus L.):: isolation, characterization, and production of jasmonates and abscisic acid in culture medium
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DOI：
10.1007/s00253-007-1077-7
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发表时间：
2007-10-01
影响因子：
5
通讯作者：
Abdala, G.
中科院分区：
文献类型：
--
作者：
Forchetti, G.;Masciarelli, O.;Abdala, G.
本研究旨在分离和鉴定向日葵（Helianthus annuus）在灌溉和水分胁迫（干旱）条件下生长的内生细菌，分析分离的细菌在干旱条件下的生长情况，并评估从干旱培养的植物中分离的细菌产生茉莉酸（JAs）和脱落酸（阿坝）的能力。从向日葵植物处于营养阶段末期时收集的土壤样品中分离细菌。从灌溉和干旱条件下生长的植物中分离到29株内生细菌。根据固氮能力，选择了8个菌株（称为SF 1至SF 8）。所有8个菌株表现出积极的过氧化氢酶和氧化酶的活动，五个菌株（SF 2，SF 3，SF 4，SF 5，SF 7）溶解磷酸盐，没有菌株产生铁载体。溶磷能力最强的菌株SF 2、SF 3、SF 4和SF 5对病原真菌Verticillum orense和Sclerotinia sclerotiorum的生长有较强的抑制作用，但对链格孢菌（Alternaria sp.）的抑制作用较弱，其中SF 2与Achromobacter xiloxidans和Alcaligenes sp.的同源性为99.9%，其余7个与短小芽孢杆菌（Bacilluspumilus）的同源性为99.9%。在对照培养基中生长的菌株SF 2、SF 3和SF 4产生茉莉酸（JA）、12-氧代-植物二烯酸（OPDA）和阿坝。这三种菌株在产生JA或OPDA的量上没有差异。阿坝含量高于JA含量，干旱条件下阿坝和JA含量均增加。这些分离的细菌菌株的特性对接种剂配方和改善向日葵作物的生长具有技术意义。
This study was designed to isolate and characterize endophytic bacteria from sunflower (Helianthus annuus) grown under irrigation and water stress (drought) conditions, to analyze growth of isolated bacteria under drought condition, and to evaluate the ability of bacteria isolated from plants cultivated under drought to produce jasmonates (JAs) and abscisic acid (ABA). Bacteria were isolated from soil samples collected when sunflower plants were at the end of the vegetative stage. A total of 29 endophytic strains were isolated from plants grown under irrigation or drought condition. Eight strains (termed SF1 through SF8) were selected based on nitrogen-fixing ability. All eight strains showed positive catalase and oxidase activities; five strains (SF2, SF3, SF4, SF5, SF7) solubilized phosphates; none of the strains produced siderophores. Strains SF2, SF3, SF4, and SF5, the ones with the highest phosphate solubilization ability, strongly inhibited growth of the pathogenic fungi Verticillum orense and Sclerotinia sclerotiorum but had less inhibitory effect on Alternaria sp. Among the eight strains, SF2 showed 99.9% sequence homology with Achromobacter xiloxidans or Alcaligenes sp., while the other seven showed 99.9% homology with Bacillus pumilus. Strains SF2, SF3, and SF4 grown in control medium produced jasmonic acid (JA), 12-oxo-phytodienoic acid (OPDA), and ABA. These three strains did not differ in amount of JA or OPDA produced. ABA content was higher than that of JA, and production of both ABA and JA increased under drought condition. The characteristics of these isolated bacterial strains have technological implications for inoculant formulation and improved growth of sunflower crops.