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פותח על ידי קלירמאש פתרונות בע"מ -
Relationship between hexokinase and cytokinin in the regulation of leaf senescence and seed germination
Year:
2011
Source of publication :
plant biology (source)
Authors :
גרנות, דוד
;
.
חנאל, רנה
;
.
שורצברג, דבורה
;
.
Volume :
13
Co-Authors:
Swartzberg, D., Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
Hanael, R., Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Granot, D., Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Facilitators :
From page:
439
To page:
444
(
Total pages:
6
)
Abstract:
Arabidopsis hexokinase (AtHXK1), an enzyme that catalyses hexose phosphorylation, accelerates leaf senescence, whereas the plant hormone cytokinin inhibits senescence. Previous work in our laboratory has shown that isopentenyl transferase (IPT), a key gene in the biosynthesis of cytokinin, expressed under promoters of the senescence-associated genes SAG12 or SAG13 (P SAG12::IPT and P SAG13::IPT, respectively), inhibits leaf senescence in tomato plants. To study the relationship between hexokinase and cytokinin in the regulation of leaf senescence, we created and analysed double-transgenic tomato plants expressing both AtHXK1 and either P SAG12::IPT or P SAG13::IPT. We found that expression of IPT in the double-transgenic plants could not prevent the accelerated senescence induced by over-expression of AtHXK1. Since cytokinin inhibits senescence via an apoplastic invertase that produces extracellular hexoses, whereas AtHXK1 is an intracellular mitochondria-associated hexokinase, our results suggest that intracellular sugar sensing via AtHXK1 is dominant over extracellular sugar sensing with regard to leaf senescence. Interestingly, the heterologous SAG12 and SAG13 promoters are also expressed in germinating tomato seed, around the radicle penetration zone, suggesting that seed germination involves a senescence process that is probably necessary for radicle emergence. Indeed, seed expressing P SAG12::IPT and P SAG13::IPT exhibited delayed radicle emergence, possibly due to delayed endosperm senescence. © 2010 German Botanical Society and The Royal Botanical Society of the Netherlands.
Note:
Related Files :
arabidopsis
gene expression
Genetics
seeds
עוד תגיות
תוכן קשור
More details
DOI :
10.1111/j.1438-8677.2010.00376.x
Article number:
0
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
22590
Last updated date:
02/03/2022 17:27
Creation date:
16/04/2018 23:53
You may also be interested in
Scientific Publication
Relationship between hexokinase and cytokinin in the regulation of leaf senescence and seed germination
13
Swartzberg, D., Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
Hanael, R., Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Granot, D., Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Relationship between hexokinase and cytokinin in the regulation of leaf senescence and seed germination
Arabidopsis hexokinase (AtHXK1), an enzyme that catalyses hexose phosphorylation, accelerates leaf senescence, whereas the plant hormone cytokinin inhibits senescence. Previous work in our laboratory has shown that isopentenyl transferase (IPT), a key gene in the biosynthesis of cytokinin, expressed under promoters of the senescence-associated genes SAG12 or SAG13 (P SAG12::IPT and P SAG13::IPT, respectively), inhibits leaf senescence in tomato plants. To study the relationship between hexokinase and cytokinin in the regulation of leaf senescence, we created and analysed double-transgenic tomato plants expressing both AtHXK1 and either P SAG12::IPT or P SAG13::IPT. We found that expression of IPT in the double-transgenic plants could not prevent the accelerated senescence induced by over-expression of AtHXK1. Since cytokinin inhibits senescence via an apoplastic invertase that produces extracellular hexoses, whereas AtHXK1 is an intracellular mitochondria-associated hexokinase, our results suggest that intracellular sugar sensing via AtHXK1 is dominant over extracellular sugar sensing with regard to leaf senescence. Interestingly, the heterologous SAG12 and SAG13 promoters are also expressed in germinating tomato seed, around the radicle penetration zone, suggesting that seed germination involves a senescence process that is probably necessary for radicle emergence. Indeed, seed expressing P SAG12::IPT and P SAG13::IPT exhibited delayed radicle emergence, possibly due to delayed endosperm senescence. © 2010 German Botanical Society and The Royal Botanical Society of the Netherlands.
Scientific Publication
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