Highest Defoliation Tolerance in Amaranthus cruentus Plants at Panicle Development Is Associated With Sugar Starvation Responses

Plant Responses to Sugar Starvation

Grain Amaranths Are Defoliation Tolerant Crop Species Capable of Utilizing Stem and Root Carbohydrate Reserves to Sustain Vegetative and Reproductive Growth after Leaf Loss

Tolerance to defoliation can be defined as the degree to which productivity is affected by photosynthetic area reduction. This trait was studied in grain amaranth (Amaranthus cruentus and A. hypochondriacus), which are considered to be a highly defoliation-tolerant species. The physiological and biochemical responses to increasing levels of mechanical leaf removal up to total defoliation were q...

Species‐specific regulation of herbivory‐induced defoliation tolerance is associated with jasmonate inducibility

Induced changes in root carbohydrate pools are commonly assumed to determine plant defoliation tolerance to herbivores. However, the regulation and species specificity of these two traits are not well understood. We determined herbivory-induced changes in root carbohydrates and defoliation tolerance in seven different solanaceous plant species and correlated the induced changes in root carbohyd...

Growth and Physiological Responses of Tundra Plants to Defoliation

In addition to extreme abiotic conditions, biotic factors such as grazing influence the growth of tundra plants. Strategies of carbon assimilation, accumulation, and utilization must not only satisfy the requirements of a rigorous physical environment but also must simultaneously adjust to the impacts associated with herbivory. Representatives of four growth forms found in northern Alaska (a de...

Is Petal Senescence Due to Sugar Starvation?

Senescence occurs at every stage of plant development. Shriveling of the cotyledons in young plants and the seasonal recurrence of leaf yellowing are obvious examples. Similarly, after pollination, petals have fulfilled their biological role and become senescent. Despite this ubiquity, however, the molecular events that initiate senescence have thus far remained a mystery. Thimann et al. (1977)...