Anatomy, histochemistry, and comparative analysis of hydroxycinnamic derivatives in healthy leaves and galls induced by Baccharopelma spp. (Hemiptera: Psyllidae) in Baccharis spicata (Lam) Baill (Asteraceae)

Abstract

Baccharis spicata is a plant native to the south of South America And is infected by psyllids of the Baccharopelma genus, which induce a fold gall in its leaves. This infection induces a series of anatomical and phytochemical variations compared to the healthy leaf: the content of total phenolic compounds and total hidroxycinnamic derivatives is lower, though the chlorogenic acid measured by HPLC remains the same and the 4,5 dichlorogenic acid content is near the half of the one observed in the one in the healthy leaf. Regarding to its anatomy, the gall has an homogeneous mesophyll and flavonoids in its outer epidermis compared to an isobilateral mesophyll and epidermal flavonoidic idioblasts observed in the leaf. The increase in the expression of waxes suggests it is a protective function against the desiccation by preventing water evaporation in the structure. The results here exposed suggest that the psyllid manipulates plant tissues, inducing hyperplasia and hypertrophy in the tissues, differentiating them from healthy structures and inducing changes in the biosynthesis of secondary polyphenolic metabolites that act like intermediary between the gall and the environment.

The mechanism of plant gall induction by insects: revealing clues, facts, and consequences in a cross-kingdom complex interaction

“…Gall morphogenesis is a complex phenomenon, which involves reorientation of the plant's development by the inducing insect (Ananthakrishnan, 1998;Raman, 2011;Oates, Külheim, Myburg, Slippers, & Naidoo, 2015;Agudelo et al, 2018). The degree to which the insect manipulates the plant's growth to form the gall varies considerably and involves changes ranging from the induction of cell proliferation (Agudelo et al, 2018) to the formation of a complex structure that the plant does not produce under normal conditions. Just like normal plant organs and structures, galls induced by insects present anatomic and histologic characteristics of their own, which vary greatly in their diversity and degree of complexity ( Fig.…”

“…Moreover, increased production of waxes in the gall induced by the insect Baccharopelma spp. (Hemiptera: Psyllidae) in leaves of Baccharis spicata (Lam) Baill has been related to a protective function against desiccation by Agudelo et al (2018).…”

“…Several authors have reported high concentrations of certain nutritive substances in gall tissues; some of those substances include sugars, proteins, phosphates, lipids, and nitrogen compounds Giron & Huguet, 2011;Huang et al, 2015;Li et al, 2017). In contrast, some researchers have described that galls can present low levels of certain chemical compounds related to the processes of plant defense, such as some phenolic compounds (Price et al, 1986;Agudelo et al, 2018).…”

“…Taking into consideration studies such as the those carried out by Nyman & Julkunen (2000), , , Giron & Huguet (2011), Huang et al (2015), Oates et al (2015), Li et al (2017), Kot et al (2017), Chen et al (2018), and Agudelo et al (2018), comparing the chemical composition of galls with that of normal plant tissue, the conclusion would be that gall-inducing insects could control some the chemical properties of these structures.…”

Anatomical, Phytochemical, and Histochemical Study of Juniperus rigida Needles at Different Altitudes

“…A lot of research for other plants has been done on the histochemistry of phenols and essential oil. The histochemistry of phenols in Baccharis spicata shows that the phenols are present in the phloem and the fiber caps (Agudelo et al, 2018). Therefore, a histochemical study of phenols and terpenoids is very important in that the results can provide information for the accumulation of secondary metabolites in J. rigida and thus add to the literature for the extensive utilization of this plant.…”