Modifying Plant Photosynthesis and Growth via Simultaneous Chloroplast Transformation of Rubisco Large and Small Subunits.
Plant Cell
; 32(9): 2898-2916, 2020 09.
Article
em En
| MEDLINE
| ID: mdl-32647068
ABSTRACT
Engineering improved Rubisco for the enhancement of photosynthesis is challenged by the alternate locations of the chloroplast rbcL gene and nuclear RbcS genes. Here we develop an RNAi-RbcS tobacco (Nicotiana tabacum) master-line, tobRrΔS, for producing homogenous plant Rubisco by rbcL-rbcS operon chloroplast transformation. Four genotypes encoding alternative rbcS genes and adjoining 5'-intergenic sequences revealed that Rubisco production was highest (50% of the wild type) in the lines incorporating a rbcS gene whose codon use and 5' untranslated-region matched rbcL Additional tobacco genotypes produced here incorporated differing potato (Solanum tuberosum) rbcL-rbcS operons that either encoded one of three mesophyll small subunits (pS1, pS2, and pS3) or the potato trichome pST-subunit. The pS3-subunit caused impairment of potato Rubisco production by â¼15% relative to the lines producing pS1, pS2, or pST However, the ßA-ßB loop Asn-55-His and Lys-57-Ser substitutions in the pS3-subunit improved carboxylation rates by 13% and carboxylation efficiency (CE) by 17%, relative to potato Rubisco incorporating pS1 or pS2-subunits. Tobacco photosynthesis and growth were most impaired in lines producing potato Rubisco incorporating the pST-subunit, which reduced CE and CO2/O2 specificity 40% and 15%, respectively. Returning the rbcS gene to the plant plastome provides an effective bioengineering chassis for introduction and evaluation of novel homogeneous Rubisco complexes in a whole plant context.
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Base de dados:
MEDLINE
Assunto principal:
Ribulose-Bifosfato Carboxilase
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Nicotiana
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Solanum tuberosum
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Cloroplastos
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article