| The thermo-sensitive chlorophyll deficient mutant Line 1103s of rice (Oryza Sativa ssp. indica) leaves is a new type of temperature sensitive chlorophyll conditional mutantion line. The bands chequered with green and chlorosis on the leaves of the thermo-sensitive rice line 1103s (Oryza sativa ssp. indica) was induced by low temperature during seedlings, called the green-yellow band. 1103s is a best material of study on metableic processes of chlorophyll .regulation of gene expression and morphological foundation of photosynthetic membrane. Therefore, the character of the whole expression processes in thermo-sensitive mutant Line 1103s of rice (Oryza Sativa ssp. indica) leaves was studied by adopting artificially controlling temperature, The major results were as follows: 1.The character of rice (Oryza Sativa ssp. indica) chequered with green and chlorosis on thermo-sensitive chlorophyll deficient mutant Line 1103s was studied when treated with varied temperature (high-low-high).The findings indicate The character appeared chequered with green and chlorosis, the critical temperature and time are 23.1# and 72 h. The data suggest that the character of rice (Oryza Sativa ssp. indica) chequered with green and chlorosis is the response to cold shock.2. ultrastructural observation on chloroplast of the thermo-sensitive green- yellow banded leaf mutant in rice ( Orym sativa ssp. indica) revealed that the chloroplast structure in the yellow part degenerated, i. e. , the number of stocks in granum abnonnally decreased, thylakoid system was disintegrated and replaced by few single thylakoid, and then the whole structure of some chloroplast became vesicle-like structure with high electronic density. Nonetheless, in the green zone of the green-yellow banded leaf, there were slight decrease in the number granum thylakoids, disordered grana arrangement in the chloroplast, and aggregation of osmiophileglobule. However, it was found that these structural alternations were reversable in the process of recovery of the yellow part of the leaves into green, and the chloroplast structure renewed normally. It might be concluded that the character of green-yellow bands induced by cold shock was consequent upon a reverse process of degeneration and regeneration.3. 1103s was a rice (Oryza sativa I.) mutant whose leaves would turn into chimerical chlorophyll deficient when treated with varied temperature (high - low - high). The alteration of whole leaf protein was studied with two-dimensional electrophoresis during the bleaching process. No changes of large subunit and small subunit of Rubisco had been detected in the bleached tissues of 1103s, but a 56.2 kD (PI = 4.5) special polypeptide- PI disappeared in the chlorosis area during the bleaching process. PI polypeptide was also detected in those tissues which remained green on the chlorophyll deficient leaves, although, its amount apparently decreased. In the tissue of low-temperature treated 1103s and 1103s x 8902s, the normal expression of PI polypeptide had been detected. The data suggest that PI is an important chlorophyll-synthesis related functional protein of response to cold shock.4. The study on metableic processes of amino acids in the thermo-sensitive chlorophyll deficient mutant indicated the total amount of the free amino acids in the yellow band of rice leaves decreased by 16% over 8902s, but the compositions of the free amino acids were not lost.The contents of Glu, Asp and NH4 in the yellow band of rice leaves increased over normal leaves; The contents of others decreased However.it was found that the alternations of amino acids contents were reversable in the process of recovery of the yellow part of the leaves into green.Glu, Asp, NH4 were located in the preceding amino acids of amino acids chains.lt might be concluded that the metableic processes of amino acids in the bands chequered with green and chlorosis were preventing regulation of the preceding amino acids.5. We had determined the Rubisco components and activity, whole leaf protein and... |
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