| Summary: | This study addresses the unique functional features of duckweed via comparison of <i>Lemna gibba</i> grown under controlled conditions of 50 versus 1000 µmol photons m<sup>−2</sup> s<sup>−1</sup> and of a <i>L. minor</i> population in a local pond with a nearby population of the biennial weed <i>Malva neglecta</i>. Principal component analysis of foliar pigment composition revealed that <i>Malva</i> was similar to fast-growing annuals, while <i>Lemna</i> was similar to slow-growing evergreens. Overall, <i>Lemna</i> exhibited traits reminiscent of those of its close relatives in the family Araceae, with a remarkable ability to acclimate to both deep shade and full sunlight. Specific features contributing to duckweed’s shade tolerance included a foliar pigment composition indicative of large peripheral light-harvesting complexes. Conversely, features contributing to duckweed’s tolerance of high light included the ability to convert a large fraction of the xanthophyll cycle pool to zeaxanthin and dissipate a large fraction of absorbed light non-photochemically. Overall, duckweed exhibited a combination of traits of fast-growing annuals and slow-growing evergreens with foliar pigment features that represented an exaggerated version of that of terrestrial perennials combined with an unusually high growth rate. Duckweed’s ability to thrive under a wide range of light intensities can support success in a dynamic light environment with periodic cycles of rapid expansion.
|
|---|