TY - JOUR
T1 - Characterization of rbcS genes in the fern Pteris vittata and their photoregulation
AU - Eilenberg, Haviva
AU - Hanania, Uri
AU - Stein, Hanan
AU - Zilberstein, Aviah
N1 - Funding Information:
We thank Dr. Lila Cohen for critical reading of the manuscript. This work was supported by the Israel Academy of Science and Humanities Basic Research Foundation (research grant No. 440/ 91)1).
PY - 1998/10
Y1 - 1998/10
N2 - The fern Pteris vittata L. belongs to the evolutionarily highest group of vascular plants that still maintains a free-living gametophytic stage. The two-dimensional gametophytes developed under blue light exhibit higher CO2 fixation efficiency and different ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) small subunit (SSU) composition when compared to the red-induced filamentous gametophytes (H. Ellenberg et al., 1991, Plant Physiol 95: 298-304). To unravel the correlation between SSU structural differences and light regulation, two rbcS genes and two additional partial cDNAs were characterized. Fern rbcS genes resemble those of higher plants in their promoter light-regulatory elements (LREs) and intron number and positions. However, the primary structure of the fern mature SSUs displays much higher divergency within the gene family. This structural variability was correlated with differential steady-state mRNA levels under red and blue light. Genes rbcS-1 and -4 show 4- to 6-fold higher transcript levels in red light while rbcS-2 and -3 contribute relatively more to the blue rbcS mRNA levels. Five of the 12 amino acids that differ between rbcS-2 and -4 affect hydrophobicity and might play a crucial role in determining the efficiency of CO2 fixation. Dendrograms of Rubisco SSUs and LSUs indicate early divergence of the fern types from the rest of the vascular plants. However, prominent higher-plant-like Rubisco features such as high carboxylation efficiency, promoter LREs and exon-intron structure, suggest that molecular specialization of the higher-plant Rubisco prototype occurred earlier than the emergence of ferns.
AB - The fern Pteris vittata L. belongs to the evolutionarily highest group of vascular plants that still maintains a free-living gametophytic stage. The two-dimensional gametophytes developed under blue light exhibit higher CO2 fixation efficiency and different ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) small subunit (SSU) composition when compared to the red-induced filamentous gametophytes (H. Ellenberg et al., 1991, Plant Physiol 95: 298-304). To unravel the correlation between SSU structural differences and light regulation, two rbcS genes and two additional partial cDNAs were characterized. Fern rbcS genes resemble those of higher plants in their promoter light-regulatory elements (LREs) and intron number and positions. However, the primary structure of the fern mature SSUs displays much higher divergency within the gene family. This structural variability was correlated with differential steady-state mRNA levels under red and blue light. Genes rbcS-1 and -4 show 4- to 6-fold higher transcript levels in red light while rbcS-2 and -3 contribute relatively more to the blue rbcS mRNA levels. Five of the 12 amino acids that differ between rbcS-2 and -4 affect hydrophobicity and might play a crucial role in determining the efficiency of CO2 fixation. Dendrograms of Rubisco SSUs and LSUs indicate early divergence of the fern types from the rest of the vascular plants. However, prominent higher-plant-like Rubisco features such as high carboxylation efficiency, promoter LREs and exon-intron structure, suggest that molecular specialization of the higher-plant Rubisco prototype occurred earlier than the emergence of ferns.
KW - Fern
KW - Photoregulation (rbcS)
KW - Pteris (rbcS regulation)
KW - Ribulose 1, 5-bisphosphate carboxylase/oxygenase
KW - rbcS
UR - http://www.scopus.com/inward/record.url?scp=0032189401&partnerID=8YFLogxK
U2 - 10.1007/s004250050392
DO - 10.1007/s004250050392
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AN - SCOPUS:0032189401
SN - 0032-0935
VL - 206
SP - 204
EP - 214
JO - Planta
JF - Planta
IS - 2
ER -