Biogenesis of Cellulose Nanofibrils by a Biological Nanomachine - The Nanoscience and Technology of Renewable Biomaterials - page 49

Figure2.3 Majorityconsensus bootstrap tree (heuristic searchmethod, 1000 replicates) of
CesA protein sequences within several plant lineages. The tree is rootedwith CesA1 from
Mesotaenium caldariorum (Mc,AAM83096),agreenalgawithrosetteCSCs(picturedatleft).
Bootstrapvalues above50are shown. Sequenceswere alignedusing thePRANKalgorithm
(defaultvalues).ByreferencetoArabidopsis,cladescontainingprimarycellwallCesAs(P1-P3)
areboxedinpink,orange,orgreen,andthosecontainingsecondarycellwallCesAs (S1-S3)
are boxed in yellow, blue, and red. Pictured at the top and bottom right, respectively, are
micrographsofsecondarycellwalls(inascanningelectronmicroscopeviewofculturedxylem
elements)andprimarycellwalls(inathinsectionofplant tissueviewedinTEM).Sequences
includedinthetreearefromPhyscomitrella patens (Pp,DQ902545,DQ902546,DQ902547,
DQ902548,DQ902549,DQ902550,DQ902551),Selaginella moellendorfii (Sm,JGIprotein
IDs:141535, 73698, 75715, 163575), Pinus taeda (Pta, AY789650, AY789651, AY789652),
Pinus radiata (Pr, AAQ63935.1), Oryza sativa (Os, AAT77342, AAP21426, BAD30574,
BAD87094,AAO41140,XM − 477282,AAP54202,BAC57282,DAA01752),andArabidopsis
thaliana (At, TAIR locus IDs: At4g32410, At4g39350, At5g05170, At5g44030, At5g09870,
At5g64740,At5g17420,At4g18780,At2g21770,At2g25540).
primary wall CesAs 1,3, and 6 have been demonstrated by bimolecular fluorescence
complementation (17). Fourth, CSC assembly and secretion depends on the presence of
a complete triad of CesA proteins coexpressed in developing xylem of Arabidopsis (24).
For primary wall CesA proteins, the region from the start of the second TMH to the
C-terminus, helps to determine which site in the CSC is accessible to a chimeric CesA
(a fusion of parts of two native CesAs) (20).