CHARACTERIZATION OF THE SENESCENCE-ASSOCIATED PROTEASES OF THE “TIGER FLOWER” (Tigridia pavonia) L.F. DC

Abstract

Background: Tigridia pavonia is a Mexican native ornamental plant that displays great beauty and color of its flower. However, its quick senescence limits its use as cut flower, since these open in the morning and close in the afternoon of the same day exhibiting wilting of tepals. Objective: In this study flower senescence process of T. pavonia was analyzed. Methodology: The expression of several proteases during senescence of tepals, ovaries and anthers was measured by SDS-PAGE and their identification was through mass spectrometry. Results: Five proteases of apparent molecular weight of 130, 90, 65, 35 and 30 kDa were expressed during flower senescence process. The 65 kDa protease was identified as cysteine-protease and had a good homology score with early responsive to dehydration protein (ERD) besides their expression coincided with the onset of visible symptoms of tepals senescence. Implications: The preliminar sequence found belonging to ERD gen indicates that it could act as the main transcription factor integrating signaling pathways that trigger flower senescence in T. pavonia. Conclusion: Flower senescence of T. pavonia is mainly associated with the expression of cysteine-proteases. One of them is possibly associated with programmed cell death in tepals.