Identification of early senescence-associated genes in rice flag leaves.
Leaf senescence is one of the key stages of plant leaf development. It is a highly complex but ordered process involving expression of large scale senescence associated genes, and its molecular mechanisms still remain unclear. By using suppression subtractive hybridization, 815 ESTs that are up-regulated at the onset of rice flag leaf senescence have been isolated. A total of 533 unigenes have been confirmed by macroarray detection and sequencing. 183 of these unigenes have GO annotations, involved in macromolecule metabolism, protein biosynthesis regulation, energy metabolism, gene expression regulations, detoxification, pathogenicity and stress, cytoskeleton organization and flower development. Another 121 unigenes co-localized with previously reported known stay-green QTLS. RT-PCR analysis on the other novel genes indicated that they can be up-regulated in natural early senescence and induced by hormone. Our results indicate that senescence is closely related to various metabolic pathways, thus providing new insight into the onset of leaf senescence mechanism.
Liu
Li
L
National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, PR China.
Zhou
Yong
Y
Zhou
Gang
G
Ye
Rongjian
R
Zhao
Lina
L
Li
Xianghua
X
Lin
Yongjun
Y
D017209:Apoptosis / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics; D002874:Chromosome Mapping; D020224:Expressed Sequence Tags; D035264:Flowers / Q000235:genetics / Q000254:growth & development; D020869:Gene Expression Profiling; D015723:Gene Library; D017343:Genes, Plant; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D014176:Protein Biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction