The involvement of the actin and the microtubule cytoskeleton networks in the gravitropic response of snapdragon ( Antirrhinum majus L.) flowering shoots was studied using various specific cytoskeleton modulators. The microtubule-depolymerizing drugs tested had no effect on gravitropic bending. In contrast, the actin-modulating drugs, cytochalasin D (CD), cytochalasin B (CB) and latrunculin B (Lat B) significantly inhibited the gravitropic response. CB completely inhibited shoot bending via inhibiting general growth, whereas CD completely inhibited bending via specific inhibition of the differential flank growth in the shoot bending zone. Surprisingly, Lat B had only a partial inhibitory effect on shoot bending as compared to CD. This probably resulted from the different effects of these two drugs on the actin cytoskeleton, as was seen in cortical cells. CD caused fragmentation of the actin cytoskeleton and delayed amyloplast displacement following gravistimulation. In contrast, Lat B caused a complete depolymerization of the actin filaments in the shoot bending zone, but only slightly reduced the amyloplast sedimentation rate following gravistimulation. Taken together, our results suggest that the actin cytoskeleton is involved in the gravitropic response of snapdragon shoots. The actin cytoskeleton within the shoot cells is necessary for normal amyloplast displacement upon gravistimulation, which leads to the gravitropic bending.
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http://dx.doi.org/10.1007/s00425-002-0957-4 | DOI Listing |
Curr Biol
January 2025
Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, SJTU-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address:
Enhancing drought resistance through the manipulation of root system architecture (RSA) in crops represents a crucial strategy for addressing food insecurity challenges. Abscisic acid (ABA) plays important roles in drought tolerance; yet, its molecular mechanisms in regulating RSA, especially in cereal crops, remain unclear. In this study, we report a new mechanism whereby ABA mediates local auxin biosynthesis to regulate root gravitropic response, thereby controlling the alteration of RSA in response to drought in cereal crops.
View Article and Find Full Text PDFPlant Sci
December 2024
Department of Life Sciences, Presidency University, 86/1 College Street, Kolkata, WB 700073, India. Electronic address:
Ubiquitous to every stratum of life, cryptochromes regulate numerous light dependent functions in terrestrial plants. These include light-dependent transcription, circadian rhythm, inhibition of hypocotyl elongation, programmed cell death, promotion of floral initiation, mediation of gravitropic response, responding to biotic and abiotic stress etc. There have been quite a few seminal reviews including on plant cryptochromes, focusing mostly on the detailed functional aspects.
View Article and Find Full Text PDFJ Adv Res
December 2024
Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, 050024, Shijiazhuang, China. Electronic address:
Background: DNA topoisomerases (TOPs) are essential components in a diverse range of biological processes including DNA replication, transcription and genome integrity. Although the functions and mechanisms of TOPs, particularly type I TOP (TOP1s), have been extensively studied in bacteria, yeast and animals, researches on these proteins in plants have only recently commenced.
Aim Of Review: In this review, the function and mechanism studies of TOP1s in plants and the structural biology of plant TOP1 are presented, providing readers with a comprehensive understanding of the current research status of this essential enzyme.
Mol Plant
January 2025
School of Biological Sciences, The University of Hong Kong, Hong Kong SAR 999077, China; Institute of Biology/Plant Physiology, Humboldt-Universität zu Berlin, Philippstrasse13, Building 12, 10115 Berlin, Germany; State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong SAR 999077, China. Electronic address:
Plant J
December 2024
College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Although geoscience of natural hydrogen (H), hydrogen-producing soil bacteria, and especially plant-based H, has been observed, it is not clear whether or how above H resources influence root gravitropic responses. Here, pharmacological, genetic, molecular, and cell biological tools were applied to investigate how plant-based H coordinates gravity responses in Arabidopsis roots. Since roots show higher H production than shoots, exogenous H supply was used to mimic this function.
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