Related Experiment Video
Updated: Jan 21, 2026
13:54
Time-lapse Fluorescence Imaging of Arabidopsis Root Growth with Rapid Manipulation of The Root Environment Using The RootChip
Published on: July 7, 2012
20.4K
Root gravity response module guides differential growth determining both root bending and apical hook formation in
Qiang Zhu1,2, Marçal Gallemí2, Jiří Pospíšil3
1Basic Forestry & Proteomics Center (BFPC), College of Forestry, Fujian Agriculture and Forestry University, 350002 Fuzhou, China.
Development (Cambridge, England)
|August 9, 2019
Summary
Root gravitropism initiates hypocotyl bending for the protective apical hook. This process relies on gradual establishment of polar auxin transport, influenced by root-hypocotyl interaction and hormone balance.
Area of Science:
- Plant biology
- Developmental biology
- Physiology
Background:
- The apical hook protects the seedling's shoot apex during soil penetration.
- Local auxin maxima are essential for apical hook formation, but the origin of this asymmetry is unclear.
- Previous studies found no auxin asymmetry in embryonic hypocotyls before hook formation.
Purpose of the Study:
- To investigate the establishment of auxin asymmetry during early seedling germination.
- To identify the initial cues that trigger hypocotyl bending for apical hook formation.
- To understand the role of root gravitropism and hormonal regulation in this process.
Main Methods:
- Analysis of auxin distribution patterns in germinating seedlings.
- Monitoring the expression of PIN auxin efflux carriers.
- Investigating the interplay between root-hypocotyl interaction and hormonal signaling (abscisic acid and gibberellins).
Main Results:
- Root bending in response to gravity is identified as the critical initial cue for hypocotyl bending.
- Auxin asymmetry is established gradually after germination begins.
- Polar auxin transport machinery develops due to root-hypocotyl interaction and a balance of abscisic acid and gibberellins.
Conclusions:
- Gravitropism-induced root bending is the primary driver for apical hook formation.
- Auxin asymmetry arises progressively post-germination, mediated by physical and hormonal interactions.
- Understanding these mechanisms is key to comprehending early plant development and adaptation.
Related Concept Videos
03:02Primary and Secondary Growth in Roots and Shoots
60.2K
Vascular plants, which account for over 90% of the Earth’s vegetation, all undergo primary growth—which lengthens roots and shoots. Many land plants, notably woody plants, also undergo secondary growth—which thickens roots and shoots.
60.2K
02:26Responses to Gravity and Touch
41.7K
Gravitropism: Plant Responses to Gravity
41.7K
00:57Root Mean Square
3.7K
If in an experiment, data values have a probability of being both positive and negative, neither the arithmetic mean, the geometric mean, nor the harmonic mean can be used to calculate the central tendency of the data set. In particular, if the positive and negative values are equally likely, the arithmetic mean is close to zero.
For example, consider the velocity of gas molecules in a container. The gas molecules are moving in different directions, which might impart positive and negative...
For example, consider the velocity of gas molecules in a container. The gas molecules are moving in different directions, which might impart positive and negative...
3.7K
02:36Meristems and Plant Growth
49.2K
Plants grow throughout their lives; this is called indeterminate growth, and it distinguishes plants from most animals. Although certain parts of plants stop growing (e.g., leaves and flowers), others grow continuously—like roots and stems.
49.2K
01:19Root-Locus Method
483
A cruise control system in a car is designed to maintain a specified speed automatically by adjusting the gas pedal. The system continuously measures the vehicle's speed and makes fine adjustments to the pedal to achieve this goal. The root locus method is particularly useful for understanding how the cruise control system's behavior changes under varying conditions, such as when the car goes uphill, downhill, or faces strong wind resistance.
This system can be represented by a block...
This system can be represented by a block...
483
01:15Construction of Root Locus
400
The construction of a root locus involves several key steps to analyze and visualize the behavior of a system's poles with varying gain. The number of branches in the root locus equals the number of closed-loop poles and is symmetrical about the real axis.
For positive gain values, the root locus exists on the real axis to the left of an odd number of finite open-loop poles or zeros. The root locus starts at the open-loop poles and traces the paths of the closed-loop poles as the gain...
For positive gain values, the root locus exists on the real axis to the left of an odd number of finite open-loop poles or zeros. The root locus starts at the open-loop poles and traces the paths of the closed-loop poles as the gain...
400