Unusual developmental morphology and anatomy of vegetative organs in Utricularia dichotoma—leaf, shoot and root dynamics

Abstract

The terrestrial carnivorous species Utricularia dichotoma is known for a great phenotypic plasticity and unusual vegetative organs. Our investigation on 22 sources/populations revealed that after initiation of a leaf and two bladders on a stolon, a bud was formed in the proximal axil of the leaf, developing into a rosette with up to seven organs. The first two primordia of the bud grew into almost every possible combination of organs, but often into two anchor stolons. The patterns were generally not population specific. The interchangeability of organs increased with increasing rank in the succession of organs on stolon nodes. A high potential of switching developmental programs may be successful in a fluctuating environment. In this respect, we were able to show that bladders developed from anchor stolons experimentally when raising the water table. Anatomical structures were simple, lacunate and largely homogenous throughout all organs. They showed similarities with many hydrophytes, reflecting the plant's adaptation to (temporarily) submerged conditions. The principal component analysis was used in the context of dynamic morphology to illustrate correlations between organ types in the morphospace of U. dichotoma, revealing an organ specific patchwork of developmental processes for typical leaves and shoots, and less pronounced for a typical root. The concept and methods we applied may prove beneficial for future studies on the evolution of Lentibulariaceae, and on developmental morphology and genetics of unusual structures in plants.

Life in the Current: Anatomy and Morphology of Utricularia neottioides

“…The leaf-like shoots of U. neottioides have a very simple anatomy, similar to that of U. reflexa (our results), U. aurea [ 31 ], U. gibba [ 32 ] and U. stygia [ 17 ], but without forming aerenchyma. These organs of aquatic Utricularia species are anatomically simpler when compared to both the large “leaves” of giant-leaved Utricularia species such as U. humboldtii with bifacial blade and palisade parenchyma [ 33 ], and also the small-leaved terrestrial species such as U. dichotoma [ 34 ], U. uniflora , and U. paulineae [ 17 ]. We observe some differences in the immunodetection of cell wall components between U. reflexa and U. neottioides .…”

Structural Features of Carnivorous Plant (Genlisea, Utricularia) Tubers as Abiotic Stress Resistance Organs

“…Orchidioides , [ 21 ] the xylem and phloem elements are separated. Vascular bundles with phloem groups flanking the xylem were observed in stolons of Utricularia dichotoma [ 6 ]. In tubers of Genlisea tuberosa and U. mannii , vascular bundles are branching in contrast to the tuber of Utricularia menziesii , with single vascular bundle in the tuber.…”

“…This type of tuber originates from a stolon with one vascular bundle. Such stolons are known for species from section Pleiochasia , to which U. menziesii belongs [ 6 ].…”

“…The Lentibulariaceae are carnivorous plants that produce three types of traps: flypaper ( Pinguicula ), eel ( Genlisea ), and suction ( Utricularia ) (e.g., [ 1 , 2 , 3 , 4 ]). Genlisea and Utricularia exhibit a novel plant architecture (e.g., [ 5 , 6 , 7 , 8 ]) linked to their growth in wet habitats. However, some are exposed seasonally to abiotic stresses such as drought, high temperatures or frost.…”

EvoDevo: Past and Future of Continuum and Process Plant Morphology

“…Members of the morphological school of Rolf Sattler [18,34,138,156] as well as Reut and Plachno [218] represented the vegetative bodies of aquatic and terrestrial bladderworts (e.g., U. foliosa, U. dichotoma) and other morphological misfits as combinations of developmental processes using multivariate statistical analyses. Plant organs such as watershoots, leaves, or bracts in U. foliosa, also various kinds of stolons in U. dichotoma are identified in the morphospace as specific process combinations (see Sections 3.6 and 3.…”