Koźmińska Aleksandra, Kamińska Iwona, Hanus-Fajerska Ewa
Department of Botany, Physiology and Plant Protection, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, Al. Mickiewicza 21, 31-120 Cracow, Poland.
Int J Mol Sci. 2024 Feb 20;25(5):2455. doi: 10.3390/ijms25052455.
The aim of this study was to investigate how introducing halophilic sulfur-oxidizing bacteria (SOB) to the growth substrate affects the physiological and biochemical responses of the halophyte (also known as sea aster or seashore aster) under salt and cadmium stress conditions. This study assessed the plant's response to these stressors and bacterial inoculation by analyzing various factors including the accumulation of elements such as sodium (Na), chloride (Cl), cadmium (Cd) and sulfur (S); growth parameters; levels of photosynthetic pigments, proline and phenolic compounds; the formation of malondialdehyde (MDA); and the plant's potential to scavenge 2,2-Diphenyl-1-picrylhydrazyl (DPPH). The results revealed that bacterial inoculation was effective in mitigating the deleterious effect of cadmium stress on some growth criteria. For instance, stem length was 2-hold higher, the growth tolerance index was 3-fold higher and there was a 20% increase in the content of photosynthetic pigments compared to non-inoculated plants. Furthermore, the SOB contributed to enhancing cadmium tolerance in by increasing the availability of sulfur in the plant's leaves, which led to the maintenance of an appropriate, about 2-fold-higher level of phenolic compounds (phenylpropanoids and flavonols), as well as chloride ions. The level of MDA decreased after bacterial application in all experimental variants except when both salt and cadmium stress were present. These findings provide novel insights into how halophytes respond to abiotic stress following inoculation of the growth medium with sulfur-oxidizing bacteria. The data suggest that inoculating the substrate with SOB has a beneficial effect on 's tolerance to cadmium stress.
本研究的目的是调查在生长基质中引入嗜盐硫氧化细菌（SOB）如何影响盐生植物（也称为海紫菀或海滨紫菀）在盐和镉胁迫条件下的生理和生化反应。本研究通过分析各种因素来评估植物对这些胁迫因素和细菌接种的反应，这些因素包括钠（Na）、氯（Cl）、镉（Cd）和硫（S）等元素的积累；生长参数；光合色素、脯氨酸和酚类化合物的水平；丙二醛（MDA）的形成；以及植物清除2,2-二苯基-1-苦基肼（DPPH）的能力。结果表明，细菌接种有效地减轻了镉胁迫对某些生长指标的有害影响。例如，与未接种细菌的植物相比，茎长增加了2倍，生长耐受指数提高了3倍，光合色素含量增加了20%。此外，SOB通过增加植物叶片中硫的有效性，有助于提高植物对镉的耐受性，这导致酚类化合物（苯丙烷类和黄酮醇）以及氯离子维持在适当的、约高2倍的水平。除了同时存在盐和镉胁迫的情况外，在所有实验变体中，细菌接种后MDA水平均下降。这些发现为盐生植物在生长培养基接种硫氧化细菌后如何应对非生物胁迫提供了新的见解。数据表明，用SOB接种基质对植物耐受镉胁迫具有有益作用。
