<span style="font-variant: small-caps">d</span>-Cysteine-Induced Rapid Root Abscission in the Water Fern <i>Azolla Pinnata</i>: Implications for the Linkage between <span style="font-variant: small-caps">d</span>-Amino Acid and Reactive Sulfur Species (RSS) in Plant Environmental Responses

• Main Authors: Hideo Yamasaki (Author), Masahiro P. Ogura (Author), Katsumi A. Kingjoe (Author), Michael F. Cohen (Author)
• Format: Book
• Published: MDPI AG, 2019-09-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS) have been proposed as universal signaling molecules in plant stress responses. There are a growing number of studies suggesting that hydrogen sulfide (H₂S) or Reactive Sulfur Species (RSS) are also involved in plant abiotic as well as biotic stress responses. However, it is still a matter of debate as to how plants utilize those RSS in their signaling cascades. Here, we demonstrate that <span style="font-variant: small-caps;">d</span>-cysteine is a novel candidate for bridging our gap in understanding. In the genus of the tiny water-floating fern <i>Azolla</i>, a rapid root abscission occurs in response to a wide variety of environmental stimuli as well as chemical inducers. We tested five H₂S chemical donors, Na₂S, GYY4137, 5a, 8l, and 8o, and found that 5a showed a significant abscission activity. Root abscission also occurred with the polysulfides Na₂S₂, Na₂S₃, and Na₂S₄. Rapid root abscission comparable to other known chemical inducers was observed in the presence of <span style="font-variant: small-caps;">d</span>-cysteine, whereas <span style="font-variant: small-caps;">l</span>-cysteine showed no effect. We suggest that <span style="font-variant: small-caps;">d</span>-cysteine is a physiologically relevant substrate to induce root abscission in the water fern <i>Azolla</i>.

Item Description

2076-3921
10.3390/antiox8090411