Amini Hajiabadi Alireza, Mosleh Arani Asghar, Ghasemi Somayeh, Rad Mohammad Hadi, Etesami Hassan, Shabazi Manshadi Shima, Dolati Ali
Central Office of Natural Resources & Watershed Management, Yazd, Iran.
Department of Environmental Sciences, Faculty of Natural Resources, Yazd University, Yazd, Iran.
Plant Physiol Biochem. 2021 Jun;163:139-153. doi: 10.1016/j.plaphy.2021.03.059. Epub 2021 Apr 4.
In this study, the effects of three halotolerant rhizobacterial isolates AL, HR, and SB, which are able to grow at a salinity level of 1600 mM NaCl, with multiple plant growth promoting (PGP) traits on some seed and forage quality attributes, and vegetative, reproductive, biochemical and physiological characteristics of wheat plant irrigated with saline water (0, 40, 80, and 160 mM NaCl) were investigated. The ability of halotolerant bacterial isolates to produce PGP traits was affected by salinity levels, depending upon the bacterial isolates. Salinity stress significantly affected the yield, quality, and growth of wheat by modifying the morpho-physiological and biochemical traits of the exposed plants. However, all three bacterial isolates, especially isolate AL, significantly improved the biochemical (an increase in K/Na ratio by 55%, plant P content by 50%, and plant Ca content by 31%), morphological (an increase in stem dry weight by 52%, root dry weight by 44%, spike dry weight by 34%, and grain dry weight by 43%), and physiological (an increase in leaf proline content by 50% and total phenol in leaf by 42%) attributes of wheat and aided the plant to tolerate salinity stress in contrast to un-inoculated plant. Plants inoculated with bacterial isolates showed significantly improved seed amylose by 36%, leaf crude protein by 30%, leaf metabolic energy by 37%, and leaf water-soluble sugar content by 34%. Among the measured PGP and plant attributes, bacterial auxin and plant K content were of key importance in increasing reproductive performance of wheat. The bacterial isolates AL, HR, and SB were identified as Bacillus safensis, B. pumilus, and Zhihengliuella halotolerans, respectively, based on 16 S rDNA sequence. The study reveals that application of halotolerant plant growth-promoting rhizobacteria isolated from halophytic rangeland plants can be a cost effective and ecological sustainable method to improve wheat productivity, especially the attributes related to seed and forage quality, under salinity stress conditions.
在本研究中，调查了三种耐盐根际细菌分离株AL、HR和SB对一些种子和饲草品质属性以及用盐水（0、40、80和160 mM NaCl）灌溉的小麦植株的营养、生殖、生化和生理特性的影响。这三种分离株能够在1600 mM NaCl的盐度水平下生长，并具有多种促进植物生长（PGP）的特性。耐盐细菌分离株产生PGP特性的能力受盐度水平的影响，具体取决于细菌分离株。盐胁迫通过改变受胁迫植物的形态生理和生化特性，显著影响了小麦的产量、品质和生长。然而，所有三种细菌分离株，尤其是分离株AL，显著改善了小麦的生化属性（钾/钠比增加55%、植物磷含量增加50%、植物钙含量增加31%）、形态属性（茎干重增加52%、根干重增加44%、穗干重增加34%、籽粒干重增加43%）和生理属性（叶片脯氨酸含量增加50%、叶片总酚含量增加42%），并帮助植株耐受盐胁迫，这与未接种的植株形成对比。接种细菌分离株的植株种子直链淀粉含量显著提高36%，叶片粗蛋白含量提高30%，叶片代谢能提高37%，叶片水溶性糖含量提高34%。在所测定的PGP和植物属性中, 细菌生长素和植物钾含量对提高小麦的生殖性能至关重要。基于16S rDNA序列，细菌分离株AL、HR和SB分别被鉴定为嗜盐芽孢杆菌、短小芽孢杆菌和耐盐志恒氏菌。该研究表明，应用从盐生牧场植物中分离的耐盐促生根际细菌，可能是一种经济有效且生态可持续的方法，可提高盐胁迫条件下小麦的生产力，尤其是与种子和饲草品质相关的属性。
