We have observed earlier that primary leaf opening in Sorghum is a light-dependent process. We now show that giving a short photo-exposure to the roots alone also induced leaf opening over a similar ...time scale. However, any injury to the primary root inhibited the leaf formation. To check the propagation rate and response in this plant, the excitable properties and capability of conduction of electrical stimulus were investigated by extracellular recordings. Sorghum seedlings (5-7 days) were examined using non-damaging electrical stimuli. We demonstrate that seedlings when stimulated in one organ, the root region, produced a characteristic response, which could be recorded further up from the stimulating region in another organ, the shoot tissue. The minimum period of stimulation was 150 µs and threshold stimulus intensity was 100 µA. The general characteristic electrophysiological properties of the seedlings and the extracellular propagation of electrical signal suggest that S. bicolor exhibit typical excitable properties comparable to neural tissues. Moreover, electrical stimulus given to the root medium could overcome the requirement of photo-exposure to induce primary leaf formation in etiolated seedlings.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Glycine-rich RNA-binding proteins play an important role in post-transcriptional regulation of gene expression, including RNA processing, and are known to be up-regulated in response to a number of ...external stimuli. However, their regulation in response to salinity stress has not been reported. We have isolated a light- and salt-regulated, full-length cDNA clone encoding a putative glycine-rich protein containing conserved ribonucleoprotein motif from
Sorghum bicolor designated as sbGR-RNP. Sequence analysis of the 701
bp insert revealed that the open reading frame of 513
bp encodes a 170 amino acid protein, with an apparent molecular mass of 16.68
kDa and calculated pI of 6.59. The deduced amino acid sequence also revealed that protein is hydrophilic in nature and contains 38% glycine residues. Northern blot analysis revealed a transcript size of 630 nucleotides, which shows regulation by blue and red light. The transcript is initially up- and down-regulated rapidly within 5
min of irradiation with blue and red light, respectively. This kind of rapid and opposite regulation by different light wavelengths could be a novel behavior of this photo-regulated gene. Furthermore, NaCl (500
mM) and abscisic acid (10
μM) also stimulated the transcript levels of sbGR-RNP to fourfold and sevenfold, respectively. These novel regulations of sbGR-RNP in response to light and salinity are important phenomena, which will be helpful in understanding the molecular mechanisms of cross-talk between abiotic stress and light signaling in plants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
74.
Fine tuning of auxin signaling by miRNAs Teotia, Preeti Singh; Mukherjee, Sunil Kumar; Mishra, Neeti Sanan
Physiology and molecular biology of plants,
04/2008, Volume:
14, Issue:
1-2
Journal Article
Peer reviewed
Open access
microRNAs (miRNAs) constitute a major class of endogenous non-coding regulatory small RNAs. They are present in a variety of organisms from algae to plants and play an important role in gene ...regulation. The miRNAs are involved in various biological processes, including differentiation, organ development, phase change, signaling, disease resistance and response to environmental stresses. This review provides a general background on the discovery, history, biogenesis and function of miRNAs. However, the focus is on the role for miRNA in controlling auxin signaling to regulate plant growth and development.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A Peep into the Plant miRNA World Mishra, Neeti Sanan; Mukherjee, Sunil Kumar
The open plant science journal,
12/2007, Volume:
1, Issue:
1
Journal Article
Peer reviewed
Open access
microRNAs constitute a major class of the small regulatory molecules that are involved in regulating the intrinsic normal growth of cells and development of organisms as well as in maintaining the ...integrity of genomes. The plant miRNA research gained momentum, 2002 onwards with identification of new miRNA molecules and their targets. This was accompanied by the discovery of plant homologs of proteins involved in miRNA biogenesis, including a new member SERRATE. The identification of several diverging and converging functions of miRNAs indicate that they play versatile roles in regulating cell differentiation and tissue development. This article provides an update on the conservation and identification of plant miRNAs. The classical miRNA biogenesis pathway and the associated proteins are discussed along with the emerging concept on the processing of miRNA-encoding introns (mirtrons). It also contains a concise account of plant miRNA targets and functions with focus on the recent successful attempt on engineering synthetic miRNAs to study gene function as well as to impart virus resistance in plants.
Light and temperature are two major environmental factors influencing plant growth and development. High temperature caused by increasing global warming and greenhouse gases has become a worldwide ...concern. In plants, it triggers various morphological, biochemical and physiological changes that adversely influence growth and development leading to substantial decrease in crop yield. The declining food production and the requirements of the rapidly growing population pose further threat to global food security. Plants have elaborate genetic and epigenetic regulatory mechanisms to endure through the unfavorable abiotic conditions. The induction of heat stress response at the genetic level involves de-regulation of transcription factors and chaperones which play an indispensable role in acclimation to heat. The epigenetic regulation includes induction or repression of specific microRNAs (miRs) that target a variety of transcripts. This is a signature response by plants that is observed in almost all stresses such as high light intensities, drought and salinity. Since earlier reports have indicated a strong relationship between light and temperature signaling pathways in plants, so their integration in influencing the miR based regulatory networks needs to be elucidated. Here we present the mirador (window designed to command an extensive outlook) on the potential role of miRs in regulating plant growth and development in synergistic response to light and heat networks.
We have observed earlier that primary leaf opening in
Sorghum is a light-dependent process. We now show that giving a short photo-exposure to the roots alone also induced leaf opening over a similar ...time scale. However, any injury to the primary root inhibited the leaf formation. To check the propagation rate and response in this plant, the excitable properties and capability of conduction of electrical stimulus were investigated by extracellular recordings.
Sorghum seedlings (5–7 days) were examined using non-damaging electrical stimuli. We demonstrate that seedlings when stimulated in one organ, the root region, produced a characteristic response, which could be recorded further up from the stimulating region in another organ, the shoot tissue. The minimum period of stimulation was 150 μs and threshold stimulus intensity was 100 μA. The general characteristic electrophysiological properties of the seedlings and the extracellular propagation of electrical signal suggest that
S. bicolor exhibit typical excitable properties comparable to neural tissues. Moreover, electrical stimulus given to the root medium could overcome the requirement of photo-exposure to induce primary leaf formation in etiolated seedlings.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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