The emission of volatiles in response to salt stress in rice cultivars has not been studied much to date. Studies addressing the regulation of stress induced volatile emission by halotolerant plant growth promoting bacteria containing ACC (1-aminocyclopropane-1-carboxylate) deaminase are also limited. The objective of the present study was to investigate the salt alleviation potential of bacteria by regulating photosynthetic characteristics and volatile emissions in rice cultivars, and to compare the effects of the bacteria inoculation and salt responses between two rice genotypes. The interactive effects of soil salinity (0, 50, and 100 mM NaCl) and inoculation with Brevibacterium linens RS16 on ACC accumulation, ACC oxidase activity, carbon assimilation and stress volatile emissions after stress application were studied in the moderately salt resistant (FL478) and the salt-sensitive (IR29) rice (Oryza sativa L.) cultivars. It was observed that salt stress reduced foliage photosynthetic rate, but induced foliage ACC accumulation, foliage ACC oxidase activity, and the emissions of all the major classes of volatile organic compounds (VOCs) including the lipoxygenase pathway volatiles, light-weight oxygenated volatiles, long-chained saturated aldehydes, benzenoids, geranylgeranyl diphosphate pathway products, and mono- and sesquiterpenes. All these characteristics scaled up quantitatively with increasing salt stress. The effects of salt stress were more pronounced in the salt-sensitive genotype IR29 compared to the moderately salt resistant FL478 genotype. However, the bacterial inoculation significantly enhanced photosynthesis, and decreased ACC accumulation and the ACC oxidase activity, and VOC emissions both in control and salt-treated plants. Taken together, these results suggested that the ACC deaminase-containing Brevibacterium linens RS16 reduces the temporal regulation of VOC emissions and increases the plant physiological activity by reducing the availability of ethylene precursor ACC and the ACC oxidase activity under salt stress.

迄今为止，对水稻品种响应盐胁迫的挥发物排放研究还很少。通过含有 ACC（1-氨基环丙烷-1-羧酸盐）脱氨酶的耐盐植物生长促进细菌调节胁迫诱导的挥发性排放的研究也很有限。本研究的目的是通过调节水稻品种的光合特性和挥发物排放来研究细菌的减盐潜力，并比较两种水稻基因型之间细菌接种和盐分反应的影响。土壤盐度（0、50 和 100 mM NaCl）与亚麻短杆菌接种的交互作用RS16对中度耐盐（FL478）和盐敏感（IR29）水稻（Oryza sativa L. ）胁迫后ACC积累、ACC氧化酶活性、碳同化和胁迫挥发物排放的影响。据观察，盐胁迫降低了叶片光合速率，但诱导了叶片 ACC 积累、叶片 ACC 氧化酶活性以及所有主要类别的挥发性有机化合物 (VOC) 的排放，包括脂氧化酶途径挥发物、轻质含氧挥发物、长-链饱和醛、苯类、香叶基香叶基二磷酸途径产物以及单萜和倍半萜。所有这些特征都随着盐胁迫的增加而定量增加。与中等抗盐性 FL478 基因型相比，盐敏感基因型 IR29 中盐胁迫的影响更为明显。然而，细菌接种显着增强了光合作用，并降低了对照和盐处理植物的 ACC 积累和 ACC 氧化酶活性以及 VOC 排放。综上所述，这些结果表明，含有 ACC 脱氨酶的亚麻短杆菌RS16 通过降低乙烯前体 ACC 的可用性和盐胁迫下的 ACC 氧化酶活性，减少了 VOC 排放的时间调节并增加了植物生理活性。