TITLE:
Evaluating Protective Terpenoid Aldehyde Compounds in Cotton (Gossypium hirsutum L.) Roots
AUTHORS:
Jodi A. Scheffler
KEYWORDS:
Cotton, Gossypol, Host Plant Resistance, Roots, Cotton Seed, Terpenoid Aldehyde
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.7 No.7,
May
18,
2016
ABSTRACT: Cotton (Gossypium hirsutum L.)
has epidermal glands containing terpenoid aldehyde (TA) compounds that protect
the plant from pests and diseases. One TA, gossypol, has two forms (+) and (-) that
are present in varying amounts. This study evaluated the variation in roots for
TA compounds and how environment affected the levels of these compounds.
Similar to seed, gossypol was the predominant TA in roots. No heliocides were
detected with only trace amounts of other TAs, such as hemigossypolone or
hemigossypol, detected in a few lines. Among the glanded lines, there were
significant differences in gossypol content. Percent plus gossypol was
consistently 4% - 10% higher in roots than seed. One line, “Mac7”, had 12 - 14
ug/mg gossypol in roots and 18 ug/mg in seed as well as >90% (+) gossypol in
both roots and seed. Unlike other tissues in glandless cotton, the roots of glandless lines consistently produced
detectable amounts of gossypol with 77% to 82% in the (+) form.
Multi-year field tests showed that although gossypol levels in the roots were
more affected by insect pressure or other environmental conditions than seed,
there was selectable variation in upland cotton for root gossypol content. Unlike
other parts of a glandless plant, the roots retained a functioning biochemical
pathway for gossypol production.