Constant Ratios of Total Chloroplast Volume to Cell Volume in Tobacco and Arabidopsis thaliana at Various Developmetal Stages

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1 Korean J. Plant Tissue Culture Vol. 28, No. 6, 311~315 (2001) Constant Ratios of Total Chloroplast Volume to Cell Volume in Tobacco and rabidopsis thaliana at Various Developmetal Stages JEONG, Won Joong PRK, Youn-IL 1 PRK, Ju Hyun MIN, Sung Ran LIU, Jang Ryol * Plant Cell iotechnology Laboratory, Korea Research Institute of ioscience and iotechnology (KRI), Taejon, , Korea 1 Department of iology, Chungnam National University, Taejon, , Korea STRCT The relationship among leaf size, leaf protoplast (cell) size, chloroplast size, and chloroplast number were investigated in tobacco and rabidopsis thaliana at various developmental stages. In tobacco, protoplasts, less than 15.6 µm in diameter had less than 20 chloroplasts, 0.93 µm in thickness and 3.3 µm in length on average. s protoplast size increased from 30 µm to 45 µm in diameter, chloroplast size remained the same (1.57 µm in diameter and 5.55 µm in length on average), but chloroplast number increase from 42 to 101 on average. similar relationship was also observed in. thaliana. The ratio of total chloroplast volume to protoplast volume was constant (0.105 in tobacco and in. thaliana) over various developmental stages. Key Words: Cell volume, chloroplast number, chloroplast volume µm (utterfass 1979) (Pyke 1997). (Dean and Leech 1982). (Ellis et al. 1983) proplastid. 20%, 70% (Ellis and Leech 1985)... *Corresponding author. Tel jrliu@mail.kribb.re.kr

2 312 Korean J. Plant Tissue Culture (Nicotiana tabacum L. cv. Xanthi) , µmol m -2 s -1. (rabidopsis thaliana (L.) Heynh. cv. Col-0) , µmol m -2 s -1. (2% cellulase Onozuka R-10, 1% Macerase R- 10, 0.6 M mannitol, 5 mm MES) confocal microscope (Zeiss LSM 410) 3. (Nikon phase contrast) ,200 (Zeiss xioskop). ( ) ( ). =π r 2 h. 1, 2, 6, 10, 16 cm 0.8, 1.2, 2.5, 3.3 cm 1 ml Figure 1. Light microscopic and confocal microscopic observations of tobacco protoplast., Light microscopic observation of tobacco protoplast;, Confocal microscopic observation of tobacco protoplast (). The bar represents 10 µm.,. (Figure 1). 2 ( 1 cm 2 cm) 0.93 µm, 3.3 µm 1.57 µm, 5.55 µm. 1 cm 2 cm, 12 µm, 15.6 µm (Figure 2, 3). C D E C D Figure 2. Changes in protoplast size, chloroplast size, and chloroplast number at various developmental stages of tobacco and rabidopsis. Left photographs: tobacco;,, C, D, and E exhibit protoplasts isolated from 1, 2, 6, 10, and 16 cm long leaf shown in the above, respectively. Right photographs: rabidopsis;,, C, and D exhibit 0.8, 1.2, 2.5, 3.3 cm long leaf, respectively, shown in the above. The bars on left and right photographs represent 20 and 10 µm, respectively.

3 313 Protoplast volume (µm 3 ) Number of choroplasts Total Chloroplast volume (µm 3 ) vol. Chloroplast / vol. protoplast Leaf size (cm 2 ) Leaf size (cm 2 ) C D Protoplast size (µm 3 ) Leaf size (cm 2 ) Figure 3. The relationship among leaf size, protoplast size, and protoplast number and the ratio of total chloroplast volume to protoplast volume in tobacco grown for 2 months in growth chamber at The light intensity was µmol m -2 s -1. Mean values ( SD) for 100 to 300 protoplasts and chloroplasts are shown. Protoplast volume (µm 3 ) Number of choroplasts Leaf size (cm 2 ) Leaf size (cm 2 ) C Total Chloroplast volume (µm 3 ) vol. Chloroplast / vol. protoplsst Figure 4. The relationship among leaf size, protoplast size, and protoplast number and the ratio of total chloroplast volume to protoplast volume in rabidopsis grown for 1 month in growth chamber at The light intensity was µmol m -2 s -1. Mean values ( SD) for 100 to 300 protoplasts and chloroplasts are shown D Protoplast size (µm 3 ) Leaf size (cm 2 )

4 314 Korean J. Plant Tissue Culture 30 µm 45 µm (Figure 2, 3). (Figure 2, 4).. ( 0.8, 1.2 cm) 1.76 µm, 4.76 µm, 2.4 µm, 5.95 µm., 15.3 µm, µm , 24.6 µm 32.6, ,. 10.5% 32.5% (Figure 3, 4)... (Possingham and Saurer 1969). wild type, (Pyke and Leech, 1992).. ( ) feedback mechanism (Pyke 1997) (density) (Pyke, 1999).. 3 photodamage mobility. Chlamydomonas photodamage mobility (Jeong et al. 2002).... (Nicotiana tabacum L cv. Xanthi) (rabidopsis thaliana cv. Col-0) µm 20, 0.93 µm, 3.3 µm. 30 µm 45 µm, 1.57 µm, 5.55 µm %, 32.5%. 21. utterfass T (1979) Patterns of Chloroplast Reproduction. Vienna, Springer-Verlag Dean C, Leech RM (1982) Genome expression during normal leaf development. I. Cellular and chloroplast numbers and DN, RN and protein levels in tissues of different ages within a seven-day old leaf. Plant Physiol. 69: Ellis JR, Jellings J, Leech RM (1983) Nuclear DN content and the control of chloroplast replication in wheat leaves. Planta. 157: Ellis JR, Leech RM (1985) Cell size and the chloroplast size in relation to chloroplast replication in light-grown wheat leaves.

5 315 Planta. 165: Jeong WJ, Park YI, Suh KH, Raven J, Yoo OJ, Liu JR (2002) large population of small chloroplasts in tobacco leaf cells allows more effective chloroplast movement than a few enlarged chloroplasts. Plant Physiol (in press) Possingham JV, Saurer W (1969) Changes in chloroplast number per cell during leaf development in spinach. Planta 86: Pyke K (1997) The genetic control of plastid division in higher plants. merican Journal of otany 84: Pyke K, Leech RM (1992) Chloroplast division and expansion is radically altered by nuclear mutations in rabidopsis thaliana. Plant Physiology 99: Pyke K (1999) Plastid division and development. Plant Cell, 11: ( )