Isozymes of nuetral and acid invertases in immature and mature internodes of sugarcane (Saccharum officinarum L.)

Date

4-2002

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Ivan Marcelo A. Duka

Co-adviser

Evelyn Mae T. Mendoza

Abstract

Bernabe, Rommel Jr. C. April 2002. University of the Philippines, Los Balms. ISOZYMES OF NEUTRAL AND ACID INVERTASES IN IMMATURE AND MATURE INTERNODES OF SUGARCANE (Saccharum officinarum L.). Adviser: Prof. Ivan Marcelo A. Duka Co-adviser: Dr. Evelyn Mae T. Mendoza

This study was conducted to determine possible isozymes of neutral (NI) and acid invertases (AI) in the different internodes of the sugarcane. Lowest activities of both invertases were observed in the immature internodes with NI and Al having 1.66 and 1.83 EU/mg protein, respectively. Their highest activities were determined as 3.51 units for AI and 3.04 units for NI in the semi-mature internodes. Activities of both enzymes started to level off in the mature internodes with NI having 2.75 units while AI having 2.14 units. These varying specific activities of neutral and acid invertases could be attributed to differential action and expression of genes during development. The shifting roles of these invertases are deemed necessary for the physiological development of the sugarcane internodes. Results from Fast Protein Liquid Chromatography-Gel Filtration Chromatography showed that one major peak labeled as HP1 and two shoulder peaks named as S1 and S2 were obtained, exhibiting NI and AI activities. These peaks showed coincident maxima for the three samples indicating the presence of similar proteins. Molecular weights of HP1, S1 and S2 were determined as 500 kDa, 10 kDa and 8 kDa. However, this study was not able to provide gel banding patterns for these fractions using SDS-PAGE. HP1, S1 and S2 invertase fractions from the immature and mature internodes were further resolved into several active peaks positive for NI and AI activities when FPLC-ion exchange chromatography was utilized. These results suggest that NI and AI isozymes of high and low molecular weights exist in immature and mature internodes of the sugarcane. This also provides the first direct evidence of NI isozymes existing in immature and mature internodes in sugarcane.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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