Changes in Polyphenol Levels in Satsuma (Citrus unshiu) Leaves in Response to Asian Citrus Psyllid Infestation and Water Stress

Abstract

Huanglongbing (HLB), also referred to as citrus greening disease has caused significant losses to the citrus industry in the United States and elsewhere. In our previous studies, we observed the fluctuation of some primary and secondary metabolites in response to biotic (psyllids feeding that transfers bacteria; i.e., Candidatus Liberibacter spp. that cause greening disease) and abiotic (water deficit) stress factors in citrus. In the current report, we evaluated the changes in polyphenolic compounds in Satsuma leaves in response to Asian citrus psyllid feeding stress and the water stress. In general, polyphenolic levels increased in Satsuma leaves in response to insect and water stress. Specifically, polyphenols such as chlorogenic acid, rutin, diosmin, luteolin7-O-glucoside, and narangin levels increased significantly in response to both biotic and abiotic stress. On the other hand, while caffeic acid levels significantly increased in water stressed plants, their levels drastically declined to the level of being undetectable in leaves stressed by psyllid feeding. Differences between the two types of stresses were also observed in the levels of apigenin 7-O-glucoside where it decreased significantly in water stressed leaves but not in leaves stressed by psyllid feeding; i.e. changes in the levels of apigenin 7-O-glucoside and caffeic acid were opposite in response to water or feeding stresses. Hesperidin levels were not affected by the water stress or by psyllid feeding. The findings may help to better understanding plant psyllid interactions and may be helpful in developing effective management practices to control the spread of citrus greening disease.

The Role of Polyphenols in Abiotic Stress Response: The Influence of Molecular Structure

“…Soil flooding increased concentrations of eriodictyol glycosides in leaves of citrus genotypes [ 70 ]. A water deficit did not affect hesperidin levels, while naringin levels increased significantly in leaves of Citrus unshiu [ 71 ]. To the contrary, in peppermint, hesperidin was significantly increased, while aglycone naringenin only slightly increased under water deficit [ 72 ].…”

Evaluation of the Effectiveness of the Combined Use of Humic Fertilizer and Herbicides in Spring Wheat Crops

“…The decrease relative to the control indicators was recorded for caffeic acid (28.6%). Under conditions of abiotic stress (drought), caffeic acid can improve the growth of roots and shoots [37] and reduce the accumulation of reactive oxygen species (ROS) [38]. In this work, we see that the content of caffeic acid has an organ-specific character.…”

An Insight into the Role of Phenolics in Abiotic Stress Tolerance in Plants: Current Perspective for Sustainable Environment

“…Water deprivation had no effect on hesperidin levels but significantly increased naringin levels in Citrus unshiu et al leaves (Table ). 30 Drought stress causes a significant increase in hesperidin levels in peppermint, whereas aglycone naringenin levels increase only marginally. 31 Tobacco plants with elevated CHS gene activity have higher levels of naringenin, particularly naringin, and are drought tolerant.…”