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Shooting through time: new insights from transcriptomic data.

Harrison CJ - Trends Plant Sci. (2015)

Bottom Line: Plant evo-devo research aims to identify the nature of genetic change underpinning the evolution of diverse plant forms.A transcriptomic study comparing gene expression profiles in the meristematic shoot tips of three distantly related vascular plants suggests that different genes were recruited to regulate similar meristematic processes during evolution.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK. Electronic address: cjh97@cam.ac.uk.

No MeSH data available.


Related in: MedlinePlus

Evolutionary innovations underpinning the radiation of vascular plant shoot architectures. (A) Illustrates key transitions in overall shoot architecture at the bryophyte–vascular plant divergence. Whereas bryophytes have a single sporophytic axis that terminates in the formation of a reproductive sporangium, vascular plants have indeterminate shoots that branch by bifurcation (lycophytes and monilophytes) or have lateral branches (angiosperms) [1]. Fossil intermediaries between living bryophytes and vascular plants (e.g., Partitatheca and Cooksonia) have branching architectures with axes that terminate in sporangium formation [2]. (B) Illustrates the morphology of leaves that evolved independently in each vascular plant lineage. Whereas lycophytes typically have small leaves with a single vein (microphylls), monilophytes typically have larger leaves with complex venation patterns (megaphylls) [1]. The monilophyte sampled by Frank et al. [5] has microphylls, but evolved from megaphyllous ancestors (not shown). (C) Shows a general trend in land plant meristem morphology. Whereas angiosperm meristems have a multicellular stem cell zone (pink) surrounded by the more rapidly proliferative peripheral zone (blue), lycophytes and monilophytes have meristems with one to a few stem cells (pink) capping a proliferative zone (blue) [1]. Amongst bryophytes [4], only mosses share meristematic attributes with vascular plants. There is a transitory apical cell (pink) that makes the apical–basal axis, and this is extended by the activity of the intercalary meristem (blue). The sporangium is located between the two, and the juxtaposition of stem cell and proliferative zones during the evolution of vascular plants may have been a key switch permitting the evolution of indeterminate meristem function. (D) Hypotheses of sister relationship between bryophytes and vascular plants are currently in flux, but a recent phylotranscriptomic analysis suggested that liverworts comprise the earliest diverging lineage, and that hornworts and mosses jointly form a monophyletic sister group to vascular plants [12]. In conjunction with functional work in Physcomitrella[6] and this tree model, the new data from Frank et al. [5] place sporophytic PIN-regulated apex function as a potential homology of stomatophytes (grey spot), and DEK1 and LOG1-regulated apex function as a homology of vascular plants (black spot). Bars represent independent origins of leaves (green) and, as suggested by Frank et al. [5], independent recruitment of genetic networks to regulate stem cell function (pink) and proliferative functions (blue) in each vascular plant group.
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fig0005: Evolutionary innovations underpinning the radiation of vascular plant shoot architectures. (A) Illustrates key transitions in overall shoot architecture at the bryophyte–vascular plant divergence. Whereas bryophytes have a single sporophytic axis that terminates in the formation of a reproductive sporangium, vascular plants have indeterminate shoots that branch by bifurcation (lycophytes and monilophytes) or have lateral branches (angiosperms) [1]. Fossil intermediaries between living bryophytes and vascular plants (e.g., Partitatheca and Cooksonia) have branching architectures with axes that terminate in sporangium formation [2]. (B) Illustrates the morphology of leaves that evolved independently in each vascular plant lineage. Whereas lycophytes typically have small leaves with a single vein (microphylls), monilophytes typically have larger leaves with complex venation patterns (megaphylls) [1]. The monilophyte sampled by Frank et al. [5] has microphylls, but evolved from megaphyllous ancestors (not shown). (C) Shows a general trend in land plant meristem morphology. Whereas angiosperm meristems have a multicellular stem cell zone (pink) surrounded by the more rapidly proliferative peripheral zone (blue), lycophytes and monilophytes have meristems with one to a few stem cells (pink) capping a proliferative zone (blue) [1]. Amongst bryophytes [4], only mosses share meristematic attributes with vascular plants. There is a transitory apical cell (pink) that makes the apical–basal axis, and this is extended by the activity of the intercalary meristem (blue). The sporangium is located between the two, and the juxtaposition of stem cell and proliferative zones during the evolution of vascular plants may have been a key switch permitting the evolution of indeterminate meristem function. (D) Hypotheses of sister relationship between bryophytes and vascular plants are currently in flux, but a recent phylotranscriptomic analysis suggested that liverworts comprise the earliest diverging lineage, and that hornworts and mosses jointly form a monophyletic sister group to vascular plants [12]. In conjunction with functional work in Physcomitrella[6] and this tree model, the new data from Frank et al. [5] place sporophytic PIN-regulated apex function as a potential homology of stomatophytes (grey spot), and DEK1 and LOG1-regulated apex function as a homology of vascular plants (black spot). Bars represent independent origins of leaves (green) and, as suggested by Frank et al. [5], independent recruitment of genetic networks to regulate stem cell function (pink) and proliferative functions (blue) in each vascular plant group.

Mentions: The conquest of land by plants was one of the most significant events in our planet's history, and the radiation of diverse plant forms was underpinned by a series of ancient innovations in sporophytic shoot architecture. Whilst living bryophyte representatives of the earliest land plants have a single sporophytic axis that terminates growth by forming a reproductive sporangium (Figure 1A), todays dominant vascular plant flora has shoots, branches and leaves under every variety of form and function (Figure 1A, B).


Shooting through time: new insights from transcriptomic data.

Harrison CJ - Trends Plant Sci. (2015)

Evolutionary innovations underpinning the radiation of vascular plant shoot architectures. (A) Illustrates key transitions in overall shoot architecture at the bryophyte–vascular plant divergence. Whereas bryophytes have a single sporophytic axis that terminates in the formation of a reproductive sporangium, vascular plants have indeterminate shoots that branch by bifurcation (lycophytes and monilophytes) or have lateral branches (angiosperms) [1]. Fossil intermediaries between living bryophytes and vascular plants (e.g., Partitatheca and Cooksonia) have branching architectures with axes that terminate in sporangium formation [2]. (B) Illustrates the morphology of leaves that evolved independently in each vascular plant lineage. Whereas lycophytes typically have small leaves with a single vein (microphylls), monilophytes typically have larger leaves with complex venation patterns (megaphylls) [1]. The monilophyte sampled by Frank et al. [5] has microphylls, but evolved from megaphyllous ancestors (not shown). (C) Shows a general trend in land plant meristem morphology. Whereas angiosperm meristems have a multicellular stem cell zone (pink) surrounded by the more rapidly proliferative peripheral zone (blue), lycophytes and monilophytes have meristems with one to a few stem cells (pink) capping a proliferative zone (blue) [1]. Amongst bryophytes [4], only mosses share meristematic attributes with vascular plants. There is a transitory apical cell (pink) that makes the apical–basal axis, and this is extended by the activity of the intercalary meristem (blue). The sporangium is located between the two, and the juxtaposition of stem cell and proliferative zones during the evolution of vascular plants may have been a key switch permitting the evolution of indeterminate meristem function. (D) Hypotheses of sister relationship between bryophytes and vascular plants are currently in flux, but a recent phylotranscriptomic analysis suggested that liverworts comprise the earliest diverging lineage, and that hornworts and mosses jointly form a monophyletic sister group to vascular plants [12]. In conjunction with functional work in Physcomitrella[6] and this tree model, the new data from Frank et al. [5] place sporophytic PIN-regulated apex function as a potential homology of stomatophytes (grey spot), and DEK1 and LOG1-regulated apex function as a homology of vascular plants (black spot). Bars represent independent origins of leaves (green) and, as suggested by Frank et al. [5], independent recruitment of genetic networks to regulate stem cell function (pink) and proliferative functions (blue) in each vascular plant group.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
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fig0005: Evolutionary innovations underpinning the radiation of vascular plant shoot architectures. (A) Illustrates key transitions in overall shoot architecture at the bryophyte–vascular plant divergence. Whereas bryophytes have a single sporophytic axis that terminates in the formation of a reproductive sporangium, vascular plants have indeterminate shoots that branch by bifurcation (lycophytes and monilophytes) or have lateral branches (angiosperms) [1]. Fossil intermediaries between living bryophytes and vascular plants (e.g., Partitatheca and Cooksonia) have branching architectures with axes that terminate in sporangium formation [2]. (B) Illustrates the morphology of leaves that evolved independently in each vascular plant lineage. Whereas lycophytes typically have small leaves with a single vein (microphylls), monilophytes typically have larger leaves with complex venation patterns (megaphylls) [1]. The monilophyte sampled by Frank et al. [5] has microphylls, but evolved from megaphyllous ancestors (not shown). (C) Shows a general trend in land plant meristem morphology. Whereas angiosperm meristems have a multicellular stem cell zone (pink) surrounded by the more rapidly proliferative peripheral zone (blue), lycophytes and monilophytes have meristems with one to a few stem cells (pink) capping a proliferative zone (blue) [1]. Amongst bryophytes [4], only mosses share meristematic attributes with vascular plants. There is a transitory apical cell (pink) that makes the apical–basal axis, and this is extended by the activity of the intercalary meristem (blue). The sporangium is located between the two, and the juxtaposition of stem cell and proliferative zones during the evolution of vascular plants may have been a key switch permitting the evolution of indeterminate meristem function. (D) Hypotheses of sister relationship between bryophytes and vascular plants are currently in flux, but a recent phylotranscriptomic analysis suggested that liverworts comprise the earliest diverging lineage, and that hornworts and mosses jointly form a monophyletic sister group to vascular plants [12]. In conjunction with functional work in Physcomitrella[6] and this tree model, the new data from Frank et al. [5] place sporophytic PIN-regulated apex function as a potential homology of stomatophytes (grey spot), and DEK1 and LOG1-regulated apex function as a homology of vascular plants (black spot). Bars represent independent origins of leaves (green) and, as suggested by Frank et al. [5], independent recruitment of genetic networks to regulate stem cell function (pink) and proliferative functions (blue) in each vascular plant group.
Mentions: The conquest of land by plants was one of the most significant events in our planet's history, and the radiation of diverse plant forms was underpinned by a series of ancient innovations in sporophytic shoot architecture. Whilst living bryophyte representatives of the earliest land plants have a single sporophytic axis that terminates growth by forming a reproductive sporangium (Figure 1A), todays dominant vascular plant flora has shoots, branches and leaves under every variety of form and function (Figure 1A, B).

Bottom Line: Plant evo-devo research aims to identify the nature of genetic change underpinning the evolution of diverse plant forms.A transcriptomic study comparing gene expression profiles in the meristematic shoot tips of three distantly related vascular plants suggests that different genes were recruited to regulate similar meristematic processes during evolution.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK. Electronic address: cjh97@cam.ac.uk.

No MeSH data available.


Related in: MedlinePlus