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Feeding on resistant rice leads to enhanced expression of defender against apoptotic cell death (OoDAD1) in the Asian rice gall midge.

Sinha DK, Atray I, Bentur JS, Nair S - BMC Plant Biol. (2015)

Bottom Line: In contrast, expression in maggots feeding on RP2068 (resistant host) showed a steep increase of more than 8-fold at 24 hai and this level was sustained at 48, 72 and 96 hai when compared with the level in maggots feeding on Jaya at 24 hai.Recombinant OoDAD1, expressed in E. coli cells, when injected into rice seedlings induced a hypersensitive response (HR) in the resistant rice host, RP2068, but not in the susceptible rice variety, Jaya.The results indicate that the expression of OoDAD1 is triggered in the feeding maggots probably due to the host resistance response and therefore, is likely an important molecule in the initial stages of the interaction between the midge and its rice host.

View Article: PubMed Central - PubMed

Affiliation: Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110 067, India. deepak22sinha@yahoo.co.in.

ABSTRACT

Background: The Asian rice gall midge (Orseolia oryzae) is a destructive insect pest of rice. Gall midge infestation in rice triggers either compatible or incompatible interactions leading to survival or mortality of the feeding maggots, respectively. In incompatible interactions, generation of plant allelochemicals/defense molecules and/or inability of the maggots to continue feeding on the host initiate(s) apoptosis within the maggots. Unraveling these molecular events, triggered within the maggots as a response to feeding on resistant hosts, will enable us to obtain a better understanding of host resistance. The present study points towards the likely involvement of a defender against apoptotic cell death gene (DAD1) in the insect in response to the host defense.

Results: The cDNA coding for the DAD1 orthologue in the rice gall midge (OoDAD1) consisted of 339 nucleotides with one intron of 85 bp and two exons of 208 and 131 nucleotides. The deduced amino acid sequence of OoDAD1 showed a high degree of homology (94.6%) with DAD1 orthologue from the Hessian fly (Mayetiola destructor)--a major dipteran pest of wheat. Southern hybridization analysis indicated that OoDAD1 was present as a single copy in the genomes of the Asian rice gall midge biotypes (GMB) 1, 4 and 4 M. In the interactions involving GMB4 with Jaya (susceptible rice host) the expression level of OoDAD1 in feeding maggots gradually increased to 3-fold at 96 hai (hours after infestation) and peaked to 3.5-fold at 96 hai when compared to that at 24 hai. In contrast, expression in maggots feeding on RP2068 (resistant host) showed a steep increase of more than 8-fold at 24 hai and this level was sustained at 48, 72 and 96 hai when compared with the level in maggots feeding on Jaya at 24 hai. Recombinant OoDAD1, expressed in E. coli cells, when injected into rice seedlings induced a hypersensitive response (HR) in the resistant rice host, RP2068, but not in the susceptible rice variety, Jaya.

Conclusions: The results indicate that the expression of OoDAD1 is triggered in the feeding maggots probably due to the host resistance response and therefore, is likely an important molecule in the initial stages of the interaction between the midge and its rice host.

No MeSH data available.


Related in: MedlinePlus

Expression of OoDAD1 in the Asian rice gall midge. Relative expression evaluated in midges feeding on susceptible [Jaya (white bars)] and resistant [RP2068 (shaded bars)] rice varieties determined using Quantitative Real-Time PCR. The time points mentioned are 24, 48, 72 and 96hai. RQ values describe the relative expression values of transcripts with reference to expression level of OoDAD1 in maggots feeding on Jaya variety (24hai). Error bars represent mean ± SD
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Fig4: Expression of OoDAD1 in the Asian rice gall midge. Relative expression evaluated in midges feeding on susceptible [Jaya (white bars)] and resistant [RP2068 (shaded bars)] rice varieties determined using Quantitative Real-Time PCR. The time points mentioned are 24, 48, 72 and 96hai. RQ values describe the relative expression values of transcripts with reference to expression level of OoDAD1 in maggots feeding on Jaya variety (24hai). Error bars represent mean ± SD

Mentions: The transcript level of OoDAD1 was assessed in a set of compatible (Jaya-GMB4) and incompatible interactions (RP2068-GMB4) (Fig. 4). The expression level of OoDAD1 transcripts at 24 h in maggots feeding on the susceptible (Jaya) host was used as a baseline and the expression at all other time points were scored relative to this. In the interactions involving GMB4 with Jaya (susceptible host) and RP2068 (resistant host), over-expression of OoDAD1 was observed in both cases. However, the expression level in maggots feeding on Jaya gradually increased by more than 3-fold at 72hai and peaked to 3.5-fold at 96hai [0.35 (log10) fold] (hours after infestation) in comparison to maggots feeding on Jaya 24hai. However, in case of maggots feeding on RP2068 there was sudden increase of expression level to 8-fold from 24hai [0.8 (log10) fold] and this enhanced expression was sustained at 48hai [0.65 (log10) fold], 72hai [0.70 (log10) fold] and 96hai [0.85 (log10) fold].Fig. 4


Feeding on resistant rice leads to enhanced expression of defender against apoptotic cell death (OoDAD1) in the Asian rice gall midge.

Sinha DK, Atray I, Bentur JS, Nair S - BMC Plant Biol. (2015)

Expression of OoDAD1 in the Asian rice gall midge. Relative expression evaluated in midges feeding on susceptible [Jaya (white bars)] and resistant [RP2068 (shaded bars)] rice varieties determined using Quantitative Real-Time PCR. The time points mentioned are 24, 48, 72 and 96hai. RQ values describe the relative expression values of transcripts with reference to expression level of OoDAD1 in maggots feeding on Jaya variety (24hai). Error bars represent mean ± SD
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4591563&req=5

Fig4: Expression of OoDAD1 in the Asian rice gall midge. Relative expression evaluated in midges feeding on susceptible [Jaya (white bars)] and resistant [RP2068 (shaded bars)] rice varieties determined using Quantitative Real-Time PCR. The time points mentioned are 24, 48, 72 and 96hai. RQ values describe the relative expression values of transcripts with reference to expression level of OoDAD1 in maggots feeding on Jaya variety (24hai). Error bars represent mean ± SD
Mentions: The transcript level of OoDAD1 was assessed in a set of compatible (Jaya-GMB4) and incompatible interactions (RP2068-GMB4) (Fig. 4). The expression level of OoDAD1 transcripts at 24 h in maggots feeding on the susceptible (Jaya) host was used as a baseline and the expression at all other time points were scored relative to this. In the interactions involving GMB4 with Jaya (susceptible host) and RP2068 (resistant host), over-expression of OoDAD1 was observed in both cases. However, the expression level in maggots feeding on Jaya gradually increased by more than 3-fold at 72hai and peaked to 3.5-fold at 96hai [0.35 (log10) fold] (hours after infestation) in comparison to maggots feeding on Jaya 24hai. However, in case of maggots feeding on RP2068 there was sudden increase of expression level to 8-fold from 24hai [0.8 (log10) fold] and this enhanced expression was sustained at 48hai [0.65 (log10) fold], 72hai [0.70 (log10) fold] and 96hai [0.85 (log10) fold].Fig. 4

Bottom Line: In contrast, expression in maggots feeding on RP2068 (resistant host) showed a steep increase of more than 8-fold at 24 hai and this level was sustained at 48, 72 and 96 hai when compared with the level in maggots feeding on Jaya at 24 hai.Recombinant OoDAD1, expressed in E. coli cells, when injected into rice seedlings induced a hypersensitive response (HR) in the resistant rice host, RP2068, but not in the susceptible rice variety, Jaya.The results indicate that the expression of OoDAD1 is triggered in the feeding maggots probably due to the host resistance response and therefore, is likely an important molecule in the initial stages of the interaction between the midge and its rice host.

View Article: PubMed Central - PubMed

Affiliation: Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110 067, India. deepak22sinha@yahoo.co.in.

ABSTRACT

Background: The Asian rice gall midge (Orseolia oryzae) is a destructive insect pest of rice. Gall midge infestation in rice triggers either compatible or incompatible interactions leading to survival or mortality of the feeding maggots, respectively. In incompatible interactions, generation of plant allelochemicals/defense molecules and/or inability of the maggots to continue feeding on the host initiate(s) apoptosis within the maggots. Unraveling these molecular events, triggered within the maggots as a response to feeding on resistant hosts, will enable us to obtain a better understanding of host resistance. The present study points towards the likely involvement of a defender against apoptotic cell death gene (DAD1) in the insect in response to the host defense.

Results: The cDNA coding for the DAD1 orthologue in the rice gall midge (OoDAD1) consisted of 339 nucleotides with one intron of 85 bp and two exons of 208 and 131 nucleotides. The deduced amino acid sequence of OoDAD1 showed a high degree of homology (94.6%) with DAD1 orthologue from the Hessian fly (Mayetiola destructor)--a major dipteran pest of wheat. Southern hybridization analysis indicated that OoDAD1 was present as a single copy in the genomes of the Asian rice gall midge biotypes (GMB) 1, 4 and 4 M. In the interactions involving GMB4 with Jaya (susceptible rice host) the expression level of OoDAD1 in feeding maggots gradually increased to 3-fold at 96 hai (hours after infestation) and peaked to 3.5-fold at 96 hai when compared to that at 24 hai. In contrast, expression in maggots feeding on RP2068 (resistant host) showed a steep increase of more than 8-fold at 24 hai and this level was sustained at 48, 72 and 96 hai when compared with the level in maggots feeding on Jaya at 24 hai. Recombinant OoDAD1, expressed in E. coli cells, when injected into rice seedlings induced a hypersensitive response (HR) in the resistant rice host, RP2068, but not in the susceptible rice variety, Jaya.

Conclusions: The results indicate that the expression of OoDAD1 is triggered in the feeding maggots probably due to the host resistance response and therefore, is likely an important molecule in the initial stages of the interaction between the midge and its rice host.

No MeSH data available.


Related in: MedlinePlus