Limits...
How and why do root apices sense light under the soil surface?

Mo M, Yokawa K, Wan Y, Baluška F - Front Plant Sci (2015)

Bottom Line: Recent biological and microscopic advances have improved our understanding of the processes involved in the sensing and transduction of light signals, resulting in subsequent physiological and behavioral responses in growing root apices.Here, we review current knowledge of cellular distributions of photoreceptors and their signal transduction pathways in diverse root tissues and root apex zones.We are discussing also the roles of auxin transporters in roots exposed to light, as well as interactions of light signal perceptions with sensing of other environmental factors relevant to plant roots.

View Article: PubMed Central - PubMed

Affiliation: College of Biological Sciences and Biotechnology, Beijing Forestry University , Beijing, China.

ABSTRACT
Light can penetrate several centimeters below the soil surface. Growth, development and behavior of plant roots are markedly affected by light despite their underground lifestyle. Early studies provided contrasting information on the spatial and temporal distribution of light-sensing cells in the apical region of root apex and discussed the physiological roles of plant hormones in root responses to light. Recent biological and microscopic advances have improved our understanding of the processes involved in the sensing and transduction of light signals, resulting in subsequent physiological and behavioral responses in growing root apices. Here, we review current knowledge of cellular distributions of photoreceptors and their signal transduction pathways in diverse root tissues and root apex zones. We are discussing also the roles of auxin transporters in roots exposed to light, as well as interactions of light signal perceptions with sensing of other environmental factors relevant to plant roots.

No MeSH data available.


Polar auxin transport based on PIN1, PIN2, and PIN3 is light sensitive and involved in the light-induced negative phototropism of roots (Friml et al., 2002; Wan et al., 2012; Zhang et al., 2014). PIN1 is involved in the acropetal (rootward) auxin transport, PIN3 in the lateral auxin transport in statocytes, and PIN2 in the basipetal (shootward) auxin transport in epidermis and cortex cells. CC, central cylinder; En, endodermis; Co, cortex; Ep, epidermis.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4585147&req=5

Figure 2: Polar auxin transport based on PIN1, PIN2, and PIN3 is light sensitive and involved in the light-induced negative phototropism of roots (Friml et al., 2002; Wan et al., 2012; Zhang et al., 2014). PIN1 is involved in the acropetal (rootward) auxin transport, PIN3 in the lateral auxin transport in statocytes, and PIN2 in the basipetal (shootward) auxin transport in epidermis and cortex cells. CC, central cylinder; En, endodermis; Co, cortex; Ep, epidermis.

Mentions: Interestingly, the phot1-GFP protein driven by an endogenous promoter is not expressed in the root cap in Arabidopsis, but has a high expression level in the apical part of the transition zone (Figure 1C; Sakamoto and Briggs, 2002; Wan et al., 2008). The root cap, a site of perception of gravity signals (Swarup et al., 2005; Leitz et al., 2009), is rather a red-light-sensing organ as PHYA and PHYB are expressed there (Figures 1B,C and 2; Adam et al., 1994; Somers and Quail, 1995a,b; Goosey et al., 1997). Therefore, the critical question is this: is the root cap also a blue light-sensing organ? Is the root cap an organ for interaction between gravity and light signals to determine tropic bending?


How and why do root apices sense light under the soil surface?

Mo M, Yokawa K, Wan Y, Baluška F - Front Plant Sci (2015)

Polar auxin transport based on PIN1, PIN2, and PIN3 is light sensitive and involved in the light-induced negative phototropism of roots (Friml et al., 2002; Wan et al., 2012; Zhang et al., 2014). PIN1 is involved in the acropetal (rootward) auxin transport, PIN3 in the lateral auxin transport in statocytes, and PIN2 in the basipetal (shootward) auxin transport in epidermis and cortex cells. CC, central cylinder; En, endodermis; Co, cortex; Ep, epidermis.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585147&req=5

Figure 2: Polar auxin transport based on PIN1, PIN2, and PIN3 is light sensitive and involved in the light-induced negative phototropism of roots (Friml et al., 2002; Wan et al., 2012; Zhang et al., 2014). PIN1 is involved in the acropetal (rootward) auxin transport, PIN3 in the lateral auxin transport in statocytes, and PIN2 in the basipetal (shootward) auxin transport in epidermis and cortex cells. CC, central cylinder; En, endodermis; Co, cortex; Ep, epidermis.
Mentions: Interestingly, the phot1-GFP protein driven by an endogenous promoter is not expressed in the root cap in Arabidopsis, but has a high expression level in the apical part of the transition zone (Figure 1C; Sakamoto and Briggs, 2002; Wan et al., 2008). The root cap, a site of perception of gravity signals (Swarup et al., 2005; Leitz et al., 2009), is rather a red-light-sensing organ as PHYA and PHYB are expressed there (Figures 1B,C and 2; Adam et al., 1994; Somers and Quail, 1995a,b; Goosey et al., 1997). Therefore, the critical question is this: is the root cap also a blue light-sensing organ? Is the root cap an organ for interaction between gravity and light signals to determine tropic bending?

Bottom Line: Recent biological and microscopic advances have improved our understanding of the processes involved in the sensing and transduction of light signals, resulting in subsequent physiological and behavioral responses in growing root apices.Here, we review current knowledge of cellular distributions of photoreceptors and their signal transduction pathways in diverse root tissues and root apex zones.We are discussing also the roles of auxin transporters in roots exposed to light, as well as interactions of light signal perceptions with sensing of other environmental factors relevant to plant roots.

View Article: PubMed Central - PubMed

Affiliation: College of Biological Sciences and Biotechnology, Beijing Forestry University , Beijing, China.

ABSTRACT
Light can penetrate several centimeters below the soil surface. Growth, development and behavior of plant roots are markedly affected by light despite their underground lifestyle. Early studies provided contrasting information on the spatial and temporal distribution of light-sensing cells in the apical region of root apex and discussed the physiological roles of plant hormones in root responses to light. Recent biological and microscopic advances have improved our understanding of the processes involved in the sensing and transduction of light signals, resulting in subsequent physiological and behavioral responses in growing root apices. Here, we review current knowledge of cellular distributions of photoreceptors and their signal transduction pathways in diverse root tissues and root apex zones. We are discussing also the roles of auxin transporters in roots exposed to light, as well as interactions of light signal perceptions with sensing of other environmental factors relevant to plant roots.

No MeSH data available.