e-journal

Nutrient reserves may allow for genome size increase: evidence from comparison of geophytes and their sister non-geophytic relatives

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† Background and Aims:
The genome size of an organism is determined by its capacity to tolerate genome expansion, given the species’ life strategy and the limits of a particular environment, and the ability for retrotransposon suppression
and/or removal. In some giant-genomed bulb geophytes, this tolerance is explained by their ability to pre-divide cells in the dormant stages or by the selective advantage of larger cells in the rapid growth of their fleshy body. In this study, a test shows that the tendency for genome size expansion is a more universal feature of geophytes, and is a subject in need of more general consideration.

† Methods:
Differences in monoploid genome sizeswere compared using standardized phylogenetically independent contrasts in 47 sister pairs of geophytic and non-geophytic taxa sampled across all the angiosperms. The genomesizes
of 96 species were adopted from the literature and 53 species were newly measured using flow cytometry with propidium iodide staining.

† Key Results:
The geophytes showed increased genomesizes compared with their non-geophytic relatives, regardless of the storage organ type and regardless of whetheror not vernal geophytes, polyploids or annualswere included in the analyses.

†Conclusions:
The universal tendency of geophytes to possess a higher genome size suggests the presence of a universal
mechanism allowing for genome expansion. It is assumed that this is primarily due to the nutrient and energetic independence of geophytes perhaps allowing continuous synthesis ofDNA,which is knownto proceed in the extreme cases of vernal geophytes even in dormant stages. This independence may also be assumed as a reason for allowing large genomes in some parasitic plants, as well as the nutrient limitation of small genomes of carnivorous plants.

Key words: Genome size evolution, Cx-value, life form, spring geophytes, ephemeroids, storage organ, energy
reserves, flow cytometry.

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Informasi Detail

Judul Seri

Annals of Botany

No. Panggil

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Penerbit

Oxford : Oxford University Press on behalf of the Annals of Botany Company., 2013

Deskripsi Fisik

Annals of Botany 112: 1193–1200, 2013

Bahasa

English

ISBN/ISSN

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Klasifikasi

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Tipe Isi

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Tipe Media

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Tipe Pembawa

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Edisi

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Subjek

EKOFISIOLOGI TANAMAN

Info Detail Spesifik

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Pernyataan Tanggungjawab

agus

Versi lain/terkait

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