Transcriptional activation of a 37 kDa ethylene responsive cysteine protease gene, RbCP1, is associated with protein degradation during petal abscission in rose.
Cysteine proteases play an important role in several developmental processes in plants, particularly those related to senescence and cell death. A cysteine protease gene, RbCP1, has been identified that encodes a putative protein of 357 amino acids and is expressed in the abscission zone (AZ) of petals in rose. The gene was responsive to ethylene in petals, petal abscission zones, leaves, and thalamus. The expression of RbCP1 increased during both ethylene-induced as well as natural abscission and was inhibited by 1-MCP. Transcript accumulation of RbCP1 was accompanied by the appearance of a 37 kDa cysteine protease, a concomitant increase in protease activity and a substantial decrease in total protein content in the AZ of petals. Agro-injection of rose petals with a 2.0 kb region upstream of the RbCP1 gene could drive GUS expression in an abscission zone-specific manner and was blocked by 1-MCP. It is concluded that petal abscission is associated with a decrease in total protein content resulting from rapid transcription of RbCP1 and the expression of a 37 kDa protease.
Plant Gene Expression Laboratory, National Botanical Research Institute, Lucknow-226001, India.
Siddharth Kaushal
SK
Tripathi
Amar Pal
AP
Singh
Aniruddha P
AP
Sane
Pravendra
P
Nath
D000595:Amino Acid Sequence; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism*; D035264:Flowers / Q000737:chemistry / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D027826:Rosa / Q000737:chemistry / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D016415:Sequence Alignment; D015533:Transcriptional Activation
D005030:Ethylenes; D010940:Plant Proteins; C036216:ethylene; D003546:Cysteine Endopeptidases