Physiological and biochemical changes in Matricaria chamomilla induced by Pseudomonas fluorescens and water deficit stress

Abstract

Environmental stresses and rhizosphere microorganisms affect growth parameters and accumulation of active ingredients especially in plants with medicinal properties. The present study examined the effects of chamomile (Matricaria chamomilla L.) seedling inoculation with Pseudomonas fluorescens PF-135 strain on its growth parameters, photosynthetic pigments, proline, malondialdehyde (MDA), and hydrogen peroxide (H 2 O 2 ) content, and essential oil concentration at both regular watering and water deficit experiments. Based on the obtained results, water deficit stress reduced root dry mass, and flower fresh and dry mass as well. However, amount of H 2 O 2 and MDA in root and shoot tissues were considerably lower in inoculated plants compared to non-inoculated ones under both normal watering and water deficit regimes. It indicates that lipid peroxidation and production of reactive oxygen species has been diminished in inoculated plants. Also, essential oil content in inoculated plants significantly increased compared with that of noninoculated ones under water deficit stress condition. It can be concluded that P. fluorescens PF-135 strain has an outstanding potential to alleviate adverse effects of water deficit on plant growth, and hence can be used as an excellent PGPR in order to boost chamomile productivity especially under water deficit stress condition.Key words: PGPR; chamomile; essential oil; injury indices; water deficit stress IZVLEČEK FIZIOLOŠKE IN BIOKEMIČNE SPREMEMBE PRAVE KAMILICE (Matricaria chamomilla L.) VZPODBUJENE Z BAKTERIJO Pseudomonas fluorescens IN POMANKANJEM VODEOkoljski stresi in mikroorganizmi v rizosferi vplivajo na rastne parametre in na kopičenje aktivnih snovi, še posebej v rastlinah z zdravilnimi lastnostmi. V raziskavi so bili preučevani učinki inokulacije sejank kamilice (Matricaria chamomilla L.) s sevom bakterije Pseudomonas fluorescens PF-135 na njene rastne parametre, vsebnost fotosinteznih barvil, prolina, malondialdehida (MDA), vodikovegan peroksida (H2O2) in eteričnih olj v razmerah rednega zalivanja in ob pomanjkanju vode. Rezultati so pokazali, da je pomanjkanje vode zmanjšalo suho maso korenin in svežo ter suho maso cvetov. Količini H2O2 in MDA v tkivih korenin in poganjkov sta bili manjši pri inokuliranih rastlina v primerjavi z neinokuliranimi pri obeh vodnih režimih. To kaže, da je bila peroksidacija lipidov in tvorba reaktivnih zvrsti kisika manjša pri inokuliranih rastlinah. Tudi vsebnost eteričnioh olj se je pri inokuliranih rastlinah značilno povečala v primerjavi z neinokuliranimi v razmerah pomanjkanja vode. Zaključili bi lahko, da ima sev bakterije P. fluorescens PF-135 izjemen potencial za odpravljanje škodljivih učinkov pomanjkanja vode na rast rastlin in bi bil lahko uporabljen kot odlična PGPR snov za povečanje pridelka kamilice, še posebej v razmerah pomanjkanja vode.

Amelioration of short‐term drought stress during different growth stages in Brassica juncea by rhizobacteria mediated maintenance of ROS homeostasis

“…Drought stress induces accumulation of ROS such as superoxide radicals and H 2 O 2 which cause lipid peroxidation of cellular membranes and protein denaturation, and consequently leads to cell death (Masoudi-Sadaghiani et al, 2011;Mohammadi et al, 2018 (Fahad et al, 2017). The enzymatic antioxidants are known to be the most potential antioxidant in scavenging ROS.…”

“…Exposure to drought leads to an increase in the accumulation of proline and total soluble sugar (TSS) that helps to maintain the plant water potential, membrane integrity, and stabilization of subcellular structures (Mohammadi et al, 2018). An increase in proline and TSS was observed in the uninoculated plants exposed to drought, probably due to osmotic adjustment (Figure 4A and B).…”

“…Drought stress induces accumulation of ROS such as superoxide radicals and H 2 O 2 which cause lipid peroxidation of cellular membranes and protein denaturation, and consequently leads to cell death (Masoudi‐Sadaghiani et al, 2011; Mohammadi et al, 2018). The level of H 2 O 2 was observed to be higher in uninoculated plants on exposure to drought stress (Table 2).…”

Optimal water and fertilizer applications improve growth of Tamarix chinensis in a coal mine degraded area under arid conditions

“…1D,E). Under stressful conditions, changes in Pro and SS levels in plants indicate an adjustment or a self‐protection mechanism to prevent protein denaturation and induce stress tolerance (Mohammadi et al 2018). In accordance with our findings, Zhou et al (2011) also demonstrated that an increase of W and N doses had a reversal effect on the accumulation of Pro and SS contents in Malcolmia africana and Bassia hyssopifolia under greenhouse conditions.…”

Chemical composition and bioactive properties of Sanguisorba minor Scop. under Mediterranean growing conditions

“…Our results revealed that the growing conditions during the period of April to May were more favourable for the peat treatment in comparison to the other substrate treatments, probably due to the better water retention properties and the alleviation of high-temperature-induced stress conditions for plants. Similarly, Baghbani-Arani et al 25 and Mohammadi et al 26 reported that water stress affects the growth of medicinal plants such as fenugreek (Trigonella foenum-graecum L.) and chamomile (Matricaria chamomilla L.).…”