Evolution of the Defense Compounds Against Biotic Stressors in the Invasive Plant Species Leucaena leucocephala

Area of Science:

• Ecology
• Plant Science
• Biochemistry

Background:

• Leucaena leucocephala is a globally invasive species threatening native plant communities.
• Its invasive success may stem from life history traits and adaptation capabilities.
• Biotic stressors like herbivores and pathogens exert pressure on plant survival and distribution.

Purpose of the Study:

• To review compounds in Leucaena leucocephala involved in defense against biotic stressors.
• To explore how these compounds contribute to the plant's invasive properties.

Main Methods:

• Literature review of studies on Leucaena leucocephala's chemical defenses.
• Analysis of compounds such as L-mimosine, flavonoids, and phenolic acids.
• Examination of the toxicological effects of these compounds on various organisms.

Main Results:

• Leucaena leucocephala contains significant amounts of L-mimosine, a toxic non-protein amino acid.
• Flavonoids, polyphenols, and benzoic/cinnamic acid derivatives are also present and exhibit toxicity.
• These compounds inactivate enzymes, disrupt cell membranes, and block DNA replication, affecting herbivores, pathogens, and competitors.

Conclusions:

• The reviewed compounds likely contribute to Leucaena leucocephala's invasive traits and survival.
• Natural selection may have favored these defensive compounds, enhancing its abundance in new ranges.
• This review is the first to focus specifically on these defense-related compounds in Leucaena leucocephala.