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Mycorrhizal-induced calmodulin mediated changes in antioxidant enzymes and growth response of drought-stressed trifoliate orange.

Huang YM, Srivastava AK, Zou YN, Ni QD, Han Y, Wu QS - Front Microbiol (2014)

Bottom Line: A 58-day of DS significantly decreased mycorrhizal colonization by 60% than WW.Compared to non-AM seedlings, AM seedlings displayed significantly higher shoot morphological properties (plant height, stem diameter, and leaf number), biomass production (shoot and root fresh weight) and leaf RWC, regardless of soil water status.The AM seedlings also exhibited significantly higher Cu/Zn-SOD and Mn-SOD activities than the non-AM seedlings under DS but not under WW, which are triggered by higher CaM levels in AM plants on the basis of correlation studies.

View Article: PubMed Central - PubMed

Affiliation: College of Horticulture and Gardening/Institute of Root Biology, Yangtze University Jingzhou, China.

ABSTRACT
Trifoliate orange [Poncirus trifoliata (L) Raf.] is considered highly arbuscular mycorrhizal (AM) dependent for growth responses through a series of signal transductions in form of various physiological responses. The proposed study was carried out to evaluate the effect of an AM fungus (Funneliformis mosseae) on growth, antioxidant enzyme (catalase, CAT; superoxide dismutase, SOD) activities, leaf relative water content (RWC), calmodulin (CaM), superoxide anion ([Formula: see text]), and hydrogen peroxide (H2O2) concentrations in leaves of the plants exposed to both well-watered (WW) and drought stress (DS) conditions. A 58-day of DS significantly decreased mycorrhizal colonization by 60% than WW. Compared to non-AM seedlings, AM seedlings displayed significantly higher shoot morphological properties (plant height, stem diameter, and leaf number), biomass production (shoot and root fresh weight) and leaf RWC, regardless of soil water status. AM inoculation significantly increased CaM and soluble protein concentrations and CAT activity, whereas significantly decreased [Formula: see text] and H2O2 concentration under both WW and DS conditions. The AM seedlings also exhibited significantly higher Cu/Zn-SOD and Mn-SOD activities than the non-AM seedlings under DS but not under WW, which are triggered by higher CaM levels in AM plants on the basis of correlation studies. Further, the negative correlation of Cu/Zn-SOD and Mn-SOD activities with [Formula: see text] and H2O2 concentration showed the DS-induced ROS scavenging ability of CaM mediated SODs under mycorrhization. Our results demonstrated that AM-inoculation elevated the synthesis of CaM in leaves and up-regulated activities of the antioxidant enzymes, thereby, repairing the possible oxidative damage to plants by lowering the ROS accumulation under DS condition.

No MeSH data available.


Related in: MedlinePlus

Effect of an AM fungus (F. mosseae) on leaf relative water content (RWC) of trifoliate orange seedlings under under WW and DS conditions. Data (means ± SD, n = 4) followed by different letters above the bars among treatments indicate significant differences at the 5% level.
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Figure 2: Effect of an AM fungus (F. mosseae) on leaf relative water content (RWC) of trifoliate orange seedlings under under WW and DS conditions. Data (means ± SD, n = 4) followed by different letters above the bars among treatments indicate significant differences at the 5% level.

Mentions: Mycorrhization significantly improved all the growth related parameters of the trifoliate orange seedlings including plant fresh weight, regardless of soil water status (Table 2). Compared with non-AMF control, AMF treatment significantly increased plant height, stem diameter, and leaf number per plant by 21, 5, and 16%, respectively, under WW and by 21, 10, and 9% under DS. Other growth parameters such as shoot, root and total plant (shoot + root) fresh weight in AM seedlings were significantly higher by 27, 23, and 26% over non-AM seedlings under WW. But under DS, the magnitude of response in shoot, root, and total plant fresh weight of AM seedlings compared to non-AM seedlings, was relatively higher by 28, 27, and 28%, respectively. Such a strongly response trend supports that AMF inoculation possessed greater ability to improve plant biomass under DS conditions than under WW conditions. Hence, AMF inoculation significantly increased shoot morphological properties (plant height, stem diameter, and leaf number) and biomass production than non-AMF control, irrespective of whether or not plants are maintained under WW and DS conditions. This is in agreement with the findings of Tian et al. (2013), who reported that AMF colonization significantly enhanced growth of Sacha inchi (Plukenetia volubilis L.) seedlings under both WW and DS conditions. The growth improvements induced by mycorrhization under either WW or DS condition have primarily been attributed to an enhancement in absorption capacity of water and nutrients by extraradical hyphae (García et al., 2008; Bárzana et al., 2012). Our observations also showed that AMF colonization significantly increased leaf RWC under both WW as well as DS conditions. Compared with non-AMF-inoculation, AMF inoculation significantly increased leaf RWC by 7 and 10% under WW and DS, respectively (Figure 2). Higher RWC in AM seedlings suggested that AM seedlings were capable of absorbing additional water from the rhizosphere or alternatively have greater ability to control water loss through stomatal regulations (Wu and Xia, 2006; Augé et al., 2014).


Mycorrhizal-induced calmodulin mediated changes in antioxidant enzymes and growth response of drought-stressed trifoliate orange.

Huang YM, Srivastava AK, Zou YN, Ni QD, Han Y, Wu QS - Front Microbiol (2014)

Effect of an AM fungus (F. mosseae) on leaf relative water content (RWC) of trifoliate orange seedlings under under WW and DS conditions. Data (means ± SD, n = 4) followed by different letters above the bars among treatments indicate significant differences at the 5% level.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4257356&req=5

Figure 2: Effect of an AM fungus (F. mosseae) on leaf relative water content (RWC) of trifoliate orange seedlings under under WW and DS conditions. Data (means ± SD, n = 4) followed by different letters above the bars among treatments indicate significant differences at the 5% level.
Mentions: Mycorrhization significantly improved all the growth related parameters of the trifoliate orange seedlings including plant fresh weight, regardless of soil water status (Table 2). Compared with non-AMF control, AMF treatment significantly increased plant height, stem diameter, and leaf number per plant by 21, 5, and 16%, respectively, under WW and by 21, 10, and 9% under DS. Other growth parameters such as shoot, root and total plant (shoot + root) fresh weight in AM seedlings were significantly higher by 27, 23, and 26% over non-AM seedlings under WW. But under DS, the magnitude of response in shoot, root, and total plant fresh weight of AM seedlings compared to non-AM seedlings, was relatively higher by 28, 27, and 28%, respectively. Such a strongly response trend supports that AMF inoculation possessed greater ability to improve plant biomass under DS conditions than under WW conditions. Hence, AMF inoculation significantly increased shoot morphological properties (plant height, stem diameter, and leaf number) and biomass production than non-AMF control, irrespective of whether or not plants are maintained under WW and DS conditions. This is in agreement with the findings of Tian et al. (2013), who reported that AMF colonization significantly enhanced growth of Sacha inchi (Plukenetia volubilis L.) seedlings under both WW and DS conditions. The growth improvements induced by mycorrhization under either WW or DS condition have primarily been attributed to an enhancement in absorption capacity of water and nutrients by extraradical hyphae (García et al., 2008; Bárzana et al., 2012). Our observations also showed that AMF colonization significantly increased leaf RWC under both WW as well as DS conditions. Compared with non-AMF-inoculation, AMF inoculation significantly increased leaf RWC by 7 and 10% under WW and DS, respectively (Figure 2). Higher RWC in AM seedlings suggested that AM seedlings were capable of absorbing additional water from the rhizosphere or alternatively have greater ability to control water loss through stomatal regulations (Wu and Xia, 2006; Augé et al., 2014).

Bottom Line: A 58-day of DS significantly decreased mycorrhizal colonization by 60% than WW.Compared to non-AM seedlings, AM seedlings displayed significantly higher shoot morphological properties (plant height, stem diameter, and leaf number), biomass production (shoot and root fresh weight) and leaf RWC, regardless of soil water status.The AM seedlings also exhibited significantly higher Cu/Zn-SOD and Mn-SOD activities than the non-AM seedlings under DS but not under WW, which are triggered by higher CaM levels in AM plants on the basis of correlation studies.

View Article: PubMed Central - PubMed

Affiliation: College of Horticulture and Gardening/Institute of Root Biology, Yangtze University Jingzhou, China.

ABSTRACT
Trifoliate orange [Poncirus trifoliata (L) Raf.] is considered highly arbuscular mycorrhizal (AM) dependent for growth responses through a series of signal transductions in form of various physiological responses. The proposed study was carried out to evaluate the effect of an AM fungus (Funneliformis mosseae) on growth, antioxidant enzyme (catalase, CAT; superoxide dismutase, SOD) activities, leaf relative water content (RWC), calmodulin (CaM), superoxide anion ([Formula: see text]), and hydrogen peroxide (H2O2) concentrations in leaves of the plants exposed to both well-watered (WW) and drought stress (DS) conditions. A 58-day of DS significantly decreased mycorrhizal colonization by 60% than WW. Compared to non-AM seedlings, AM seedlings displayed significantly higher shoot morphological properties (plant height, stem diameter, and leaf number), biomass production (shoot and root fresh weight) and leaf RWC, regardless of soil water status. AM inoculation significantly increased CaM and soluble protein concentrations and CAT activity, whereas significantly decreased [Formula: see text] and H2O2 concentration under both WW and DS conditions. The AM seedlings also exhibited significantly higher Cu/Zn-SOD and Mn-SOD activities than the non-AM seedlings under DS but not under WW, which are triggered by higher CaM levels in AM plants on the basis of correlation studies. Further, the negative correlation of Cu/Zn-SOD and Mn-SOD activities with [Formula: see text] and H2O2 concentration showed the DS-induced ROS scavenging ability of CaM mediated SODs under mycorrhization. Our results demonstrated that AM-inoculation elevated the synthesis of CaM in leaves and up-regulated activities of the antioxidant enzymes, thereby, repairing the possible oxidative damage to plants by lowering the ROS accumulation under DS condition.

No MeSH data available.


Related in: MedlinePlus