Publicação on-line; 36 ref.; 3 tables; 2 illus.; Summary (En)

Abstract

An overview about ultrastructure of Kranz anatomy in Cyperaceae (Poales) - The ultrastructure of the Kranz
tissues in Cyperaceae species with the four types of Kranz anatomy (chlorocyperoid, eleocharoid, fimbristyloid
and rhynchosporoid) was studied and compared with species already described in the literature, with
the goal verifying the occurrence of patterns for the Kranz types. In addition, chloroplasts and mitochondria
were quantified for the first time for all Kranz types. The chloroplast’s structure is similar in the mesophyll
cells (PCA) in the four Kranz types, but differs in some features in the bundle sheath cells (PCR). In the
chlorocyperoid and rhynchosporoid types the bundle sheath cells (PCR) present centrifugal or scattered
chloroplasts with convoluted or parallel thylakoids. In the eleocharoid types, the chloroplasts are scattered
with parallel thylakoids. The fimbristyloid type presents centrifugal chloroplasts with convoluted and parallel
thylakoids. To eleocharoid and fimbristyloid types and to Cyperus and Pycreus (chlorocyperoid) was observed
pattern in the chloroplasts position. In most of the studied species the number of mitochondria in the bundle
sheath cells (PCR) is significantly higher than in the mesophyll cells (PCA) and this result diverges from the
results found in previous studies.

Key words: C4 photosynthesis, chloroplast, mitochondria, Cyperaceae, Kranz.