The myeloblastosis oncogenes(MYB)are important transcription factors that facilitate induction of variously develop-mental and stress responsive genes.They are hence,emerging as key players in improving stress toleran...The myeloblastosis oncogenes(MYB)are important transcription factors that facilitate induction of variously develop-mental and stress responsive genes.They are hence,emerging as key players in improving stress tolerance of plants in response to several abiotic stresses.It was predicted that DfMYB2 contained an open reading frame(ORF)of 1621 bp coding 377 amino acid residues with molecular weight of 41.5 ku.It had 50 potential phosphorylation sites,44 potential N-glycosylation sites and one trans-membrane domain.In neighbor-joining(NJ)phylogenetic tree,DfMYB2 was close to the branch of angiosperms.The subcellular localization of DfMYB2 was in nucleus.The expressions of DfMYB2 increased gradually in the filament,prothalli and sporophyte.The results showed that DfMYB2 played a more and more important role in its growth and development.And the expression levels in rhizomes were significantly higher than those in roots and leaves.After abscisic acid(ABA)and PEG600 treatment,DfMYB2 showed a downward trend,followed by an upward trend.The expression of DfMYB2 was inhibited in a short time under drought stress,the strong induction of DfMYB2 expression by ABA indicated that it was possibly involved in abiotic stress responses in an ABA-dependent manner.展开更多
Superoxide dismutases （SODs） are a group of important antioxidant defense enzymes. In this study, a putative extracellular Cu/Zn superoxide dismutase （ecCuZnSOD） complementary DNA was cloned and characterized from...Superoxide dismutases （SODs） are a group of important antioxidant defense enzymes. In this study, a putative extracellular Cu/Zn superoxide dismutase （ecCuZnSOD） complementary DNA was cloned and characterized from the whitefly, Bemisia tabaci. Quantitative polymerase chain reaction analysis showed that the expression level of BtecCuZnSOD was more than 10-fold higher in the invasive Middle East Asia Minor 1 （MEAM1） than in the native Asia II 3 species of the B. tabaci species complex. After exposure to low temperature （4 ℃）, the expression of Bt-ecCuZnSOD gene was significantly up-regulated in MEAM1 but not in Asia II 3. Furthermore, the expression level ofB. tabaci intracellular CuZnSOD （Bt-icCuZnSOD）, Bt-ecCuZnSOD and mitochondrial MnSOD （Bt-mMnSOD） was compared after transferring MEAM1 and Asia II 3 whiteflies from favorable （cotton） to unfavorable host plants （tobacco）. On cotton, both CuZnSOD genes were expressed at a higher level in MEAM1 compared with Asia II 3. Interestingly, after transferring onto tobacco, the expression of Bt-ecCuZnSOD was significantly induced in Asia II 3 but not in MEAM1. On the other hand, while Bt-mMnSOD was expressed equally in both species on cotton, Bt-mMnSOD messenger RNA was up-regulated in MEAM 1 on tobacco. Consistently, enzymatic activity assays of CuZnSOD and MnSOD demonstrated that CuZnSOD might play an important protective role against oxidative stress in Asia II 3, whereas MnSOD activation was critical for MEAM1 whiteflies during host adaptation. Taken together, our results suggest that the successful invasion ofMEAM 1 is correlated with its constitutive high activity of CuZnSOD and inducible expression of MnSOD under stress conditions.展开更多
基金Supported by the National Natural Science Foundation of China(31570189)。
文摘The myeloblastosis oncogenes(MYB)are important transcription factors that facilitate induction of variously develop-mental and stress responsive genes.They are hence,emerging as key players in improving stress tolerance of plants in response to several abiotic stresses.It was predicted that DfMYB2 contained an open reading frame(ORF)of 1621 bp coding 377 amino acid residues with molecular weight of 41.5 ku.It had 50 potential phosphorylation sites,44 potential N-glycosylation sites and one trans-membrane domain.In neighbor-joining(NJ)phylogenetic tree,DfMYB2 was close to the branch of angiosperms.The subcellular localization of DfMYB2 was in nucleus.The expressions of DfMYB2 increased gradually in the filament,prothalli and sporophyte.The results showed that DfMYB2 played a more and more important role in its growth and development.And the expression levels in rhizomes were significantly higher than those in roots and leaves.After abscisic acid(ABA)and PEG600 treatment,DfMYB2 showed a downward trend,followed by an upward trend.The expression of DfMYB2 was inhibited in a short time under drought stress,the strong induction of DfMYB2 expression by ABA indicated that it was possibly involved in abiotic stress responses in an ABA-dependent manner.
基金Acknowledgments Financial support for this study was provided by the National Natural Science Foundation of China （Projects 31071686, 31171848）, the Program for New Century Excellent Talents in University （NCET-12-0483） and the Specialized Research Fund for the Doctoral Program of Higher Education （Project 20120101110077）.
文摘Superoxide dismutases （SODs） are a group of important antioxidant defense enzymes. In this study, a putative extracellular Cu/Zn superoxide dismutase （ecCuZnSOD） complementary DNA was cloned and characterized from the whitefly, Bemisia tabaci. Quantitative polymerase chain reaction analysis showed that the expression level of BtecCuZnSOD was more than 10-fold higher in the invasive Middle East Asia Minor 1 （MEAM1） than in the native Asia II 3 species of the B. tabaci species complex. After exposure to low temperature （4 ℃）, the expression of Bt-ecCuZnSOD gene was significantly up-regulated in MEAM1 but not in Asia II 3. Furthermore, the expression level ofB. tabaci intracellular CuZnSOD （Bt-icCuZnSOD）, Bt-ecCuZnSOD and mitochondrial MnSOD （Bt-mMnSOD） was compared after transferring MEAM1 and Asia II 3 whiteflies from favorable （cotton） to unfavorable host plants （tobacco）. On cotton, both CuZnSOD genes were expressed at a higher level in MEAM1 compared with Asia II 3. Interestingly, after transferring onto tobacco, the expression of Bt-ecCuZnSOD was significantly induced in Asia II 3 but not in MEAM1. On the other hand, while Bt-mMnSOD was expressed equally in both species on cotton, Bt-mMnSOD messenger RNA was up-regulated in MEAM 1 on tobacco. Consistently, enzymatic activity assays of CuZnSOD and MnSOD demonstrated that CuZnSOD might play an important protective role against oxidative stress in Asia II 3, whereas MnSOD activation was critical for MEAM1 whiteflies during host adaptation. Taken together, our results suggest that the successful invasion ofMEAM 1 is correlated with its constitutive high activity of CuZnSOD and inducible expression of MnSOD under stress conditions.
