Leaf senescence is delayed in maize expressing the Agrobacterium IPT gene under the control of a novel maize senescence-enhanced promoter

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dc.contributor.author Frame, Bronwen
dc.contributor.author Thomas, Howard
dc.contributor.author Thomas, Ann M.
dc.contributor.author Wang, Kan
dc.contributor.author Donnison, Iain S.
dc.contributor.author Robson, Paul R. H.
dc.contributor.author Pegg, Sue Ellen
dc.date.accessioned 2009-09-08T08:27:33Z
dc.date.available 2009-09-08T08:27:33Z
dc.date.issued 2009-09-08
dc.identifier.citation Frame , B , Thomas , H , Thomas , A M , Wang , K , Donnison , I S , Robson , P R H & Pegg , S E 2009 , ' Leaf senescence is delayed in maize expressing the Agrobacterium IPT gene under the control of a novel maize senescence-enhanced promoter ' Plant Biotechnology Journal , pp. 101-112 . en
dc.identifier.other PURE: 129325
dc.identifier.other dspace: 2160/2975
dc.identifier.uri http://hdl.handle.net/2160/2975
dc.description Robson, P. R. H., Donnison, I. S., Wang, K., Frame, B., Pegg, S. E., Thomas, A., Thomas, Howard (2004). Leaf senescence is delayed in maize expressing the Agrobacterium IPT gene under the control of a novel maize senescence-enhanced promoter. Plant Biotechnology Journal, 2, (2), 101-112 en
dc.description.abstract We have genetically modified maize plants to delay leaf senescence. A senescence-enhanced promoter from maize (PSEE1) was used to drive expression of the Agrobacterium cytokinin biosynthesis gene IPT in senescing leaf tissue. Three maize lines expressing IPT from PSEE1, Sg1, Sg2 and Sg3, were analysed in detail, representing mild, intermediate and extreme expression, respectively, of the delayed-senescence phenotype. Backcross populations segregating for the presence or absence of the PSEE1XbaIPTNOS transgene also simultaneously segregated for the senescence phenotype. At the time of ear leaf emergence, individuals of lines Sg1 and Sg2 segregating for the presence of the transgene carried about three fewer senescing leaves than control (transgene-minus) segregants, and IPT transcript levels were higher in leaves at incipient senescence than in young leaves. Leaves of transgenic Sg3 plants were significantly greener than controls and progressed directly from fully green to bleached and dead without an intervening yellowing phase. IPT transcript abundance in this line was not related to the initiation of senescence. Extended greenness was accompanied by a delay in the loss of photosynthetic capacity with leaf age. The delayed-senescence trait was associated with relatively minor changes in morphology and development. The phenotype was particularly emphasized in plants grown in low soil nitrogen. The reduced ability of the extreme transgenic line Sg3 to recycle internal nitrogen from senescing lower leaves accounted for significant chlorosis in emerging younger leaves when plants were grown in low nutrient conditions. This study demonstrates that the agronomically important delayed-senescence ('stay-green') trait can be engineered into a monocot crop, and is the first example outside Arabidopsis of senescence modification using a homologous senescence-enhanced promoter. en
dc.format.extent 12 en
dc.language.iso eng
dc.relation.ispartof Plant Biotechnology Journal en
dc.title Leaf senescence is delayed in maize expressing the Agrobacterium IPT gene under the control of a novel maize senescence-enhanced promoter en
dc.type Text en
dc.type.publicationtype Article (Journal) en
dc.contributor.institution Institute of Biological, Environmental and Rural Sciences en
dc.description.status Peer reviewed en


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