Journal
JOURNAL OF PLANT PHYSIOLOGY
Volume 216, Issue -, Pages 181-187Publisher
ELSEVIER GMBH
DOI: 10.1016/j.jplph.2017.07.001
Keywords
Auxin; Gravitropism; NADH oxidase; Reactive oxygen species; Seed germination; Vigna radiata
Categories
Funding
- University Grants Commission, New Delhi [39-375/2010]
Ask authors/readers for more resources
In plant establishment, seed germination is characterized by the emergence of a radicle for secured anchorage to the soil and nutrient and water uptake. Early growth of germinating axes appears to be gravisensitive, and the regulation of this process is largely uncharacterized, particularly in case of epigeally germinating species. Our previous work on the germination of Vigna radiata seeds demonstrated the role of apoplastic reactive oxygen species (ROS) in germination-associated axis growth. This study attempts to explore a possibly similar role of ROS in the gravitropic bending of germinating axes. Pharmacological and histological studies correlated the curvature growth of the axis (due to cell elongation in the cortical region of the upper side) with apoplastic superoxide accumulation. The superoxide was produced by diphenylene iodonium chloride (DPI)-insensitive NADH oxidase, which was different from the DPI-sensitive NADPH oxidase active in the apical elongation zone of the radicle. This NADH oxidase was differentially controlled by IAA, and its activation required influx of apoplastic Ca2+. This study shows that the early axis growth in germinating seeds is gravisensitive, which is distinct spatially as well as temporally from the elongation growth of the axis (radicle) and controlled by auxin and cytosolic Ca2+ through NADH oxidase-dependent ROS production.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available