Growth cycle and dormancy in plants.

Okubo, Hiroshi; Viémont, Jean-Daniel; Crabbé, J.

doi:10.1079/9780851994475.0001

Cited by 20 publications

(16 citation statements)

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“…Growth of rice (Oryza sativa L.) seedling is characterized primarily by two major events of meristematic growth, the first at the time of germination and the second at the time of flowering (Okubo, 2000). The differentiation for the early vegetative growth occurs during embryogenesis itself (Sato et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Respiration hastens maturation and lowers yield in rice

Sitaramam

Bhate

Kamalraj

et al. 2008

Physiol Mol Biol Plants

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Role of respiration in plant growth remains an enigma. Growth of meristematic cells, which are not photosynthetic, is entirely driven by endogenous respiration. Does respiration determine growth and size or does it merely burn off the carbon depleting the biomass? We show here that respiration of the germinating rice seed, which is contributed largely by the meristematic cells of the embryo, quantitatively correlates with the dynamics of much of plant growth, starting with the time for germination to the time for flowering and yield. Seed respiration appears to define the quantitative phenotype that contributes to yield via growth dynamics that could be discerned even in commercial varieties, which are biased towards higher yield, despite considerable susceptibility of the dynamics to environmental perturbations. Intrinsic variation, irreducible despite stringent growth conditions, required independent validation of relevant physiological variables both by critical sampling design and by constructing dendrograms for the interrelationships between variables that yield high consensus. More importantly, seed respiration, by mediating the generation clock time via variable time for maturation as seen in rice, directly offers the plausible basis for the phenotypic variation, a major ecological stratagem in a variable environment with uncertain water availability. Faster respiring rice plants appear to complete growth dynamics sooner, mature faster, resulting in a smaller plant with lower yield. Counter to the common allometric views, respiration appears to determine size in the rice plant, and offers a valid physiological means, within the limits of intrinsic variation, to help parental selection in breeding.

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Section: Introductionmentioning

confidence: 99%

Respiration hastens maturation and lowers yield in rice

Sitaramam

Bhate

Kamalraj

et al. 2008

Physiol Mol Biol Plants

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“…Despite numerous publications on dormancy classification (Lang et al, 1987; Okubo, 2000), this phenomenon is still not well understood and does not even have an established terminology. In the case of geophytes, for example, it was suggested that a state of dormancy was one in which bulbs do not exhibit any visible external growth (Le Nard and De Hertogh, 1993).…”

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confidence: 99%

“…Le Nard (1983) proposed applying the term dormancy to the entire plant and therefore to define dormancy as a period during which a bud is unable to react to environmental factors. According to Okubo (2000), dormancy is considered to be the regulation imposed on the progress in the growth process at various stages, with or without morphological modifications. The terms rest , quiescence , intrabulb development , or growth arrest are also used in the literature on perennial plants to emphasize the fact that their meristems might remain active during unfavorable seasons.…”

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confidence: 99%

Patterns of Dormancy and Florogenesis in Herbaceous Perennial Plants: Environmental and Internal Regulation

Kamenetsky

2009

Crop Science

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Plant evolution in climatic areas with marked seasonal changes has led to species adaptation to periods of high and low temperatures and drought and to significant changes in their morphological structure and annual developmental cycles. One characteristic of these adaptations is the state of dormancy, in which the plants do not exhibit any visible external growth. This paper reviews dormancy and florogenesis as main components of the survival strategies of perennial herbaceous plants. Summer dormancy protects plants from negative effects of water deficit and high temperatures on vegetative and reproductive organs, and forces plant species to schedule their active development in more favorable seasons. Mechanisms of summer survival vary among species and provide different modes of adaptation to harsh environments. The interrelationship between florogenesis and dormancy is most probably controlled in meristems, where the survival strategy of the plant, including vegetative growth, flowering, drought tolerance, and formation of storage organs, is determined. Mechanisms by which summer dormancy confers summer drought survival warrant further investigation for improving agronomic and environmental traits of perennial plants.

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“…Among the same species, this climatic variations generated different genotypes with a distinct dormancy intensity (Heide et al, 1977). In cases where this pressure was released, some annual plants at the tropical climates have been observed to reconstitute their ancestral woody or evergrowing habit (Okubo et al, 2000). …”

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confidence: 99%

Molecular aspects of dormancy in peach (Prunus persica [L.] Batsch.)

Leida¹

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En estos cuatros años en los que he estado trabajando, he conocido a mucha gente que me ha ayudado en distintas formas para la realización de esta tesis y por eso he pensado en agradecerlos.En primer lugar quería dar las gracias a mis directores por la dedicación que me han prestado. A Gerardo y Marisa por darme la oportunidad de trabajar en el IVIA y de desarrollar esta tesis. A Gabino por haber estado ahí en todo momento, para enseñar y contestar a mis preguntas, sin su apoyo no habría podido llegar hasta aquí. ABSTRACTDormancy is one of the most important adaptive mechanisms developed by perennial plants, in order to survive the low temperatures of autumn and winter in temperate climates. The study of the genes regulated during dormancy release is crucial to understand the process, with the final objective of the development of new varieties with a better adaptation to certain environments; and this is particularly important considering the increasing economical weight of fruit crops in low and medium chilling regions as the Mediterranean area. We focused on the molecular and physiological mechanisms underlying the maintenance and release of seasonal dormancy in peach. In order to achieve this we first used suppression subtractive hybridization (SSH) to identify genes expressed in dormant and dormancy-released buds in two cultivars with different chilling requirements, 'Zincal-5' and 'Springlady', and subsequently validated their differential expression utilizing a peach cDNA microarray platform containing transcripts enriched in flower buds. Additionally, we carried out a genome-wide search of peach genes related to dormancy release by hybridizing the previous cDNA microarray with mRNA samples from 10 cultivars showing different dormancy behaviour, followed by an expression correlation analysis.Among the most relevant genes identified in these two first works, we found the DORMANCY ASSOCIATED MADS-box genes DAM4, DAM5 and DAM6, described independently by other groups working in peach and other species. The central role of DAM genes in dormancy regulation has also been confirmed by additional functional approaches as the analysis of the non-dormant evg mutant, QTL analysis, and transgenic approaches.In our second work we focused on the molecular mechanisms of DAM6 down-regulation concomitant with dormancy release in flower buds. A ChIP analysis of DAM6 promoter and structural gene revealed chromatin modification events similar to those observed in vernalization of Arabidopsis and cereals. We showed that DAM6 is transcriptionally active in dormant buds collected in October, when a short chromatin region around its ATG was trimethylated in histone H3 at K4 (H3K4) and acetylated at the N-terminal tail of H3. Concomitantly with DAM6 repression, H3K4 became demethylated and H3 deacetylated. Later H3K27 was found trimethylated along a genomic region larger than 4kb, including promoter, coding sequence and intron. Due to their relevance in dormancy regulation, DAM genes could be used as expression markers to assess...

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Growth cycle and dormancy in plants.

Cited by 20 publications

References 0 publications

Respiration hastens maturation and lowers yield in rice

Respiration hastens maturation and lowers yield in rice

Patterns of Dormancy and Florogenesis in Herbaceous Perennial Plants: Environmental and Internal Regulation

Molecular aspects of dormancy in peach (Prunus persica [L.] Batsch.)

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