Figure 4
Comparison of Arabidopsis AtPP2-A -modified mutants and WT plant in colonization and phloem feeding by aphids. (a) Changes of aphid population in 24 hours. Plants were treated with HrpNEa and EVP, respectively. Five days later, uniform aphids were placed on lower sides of the top two expanded leaves (10 aphids/leaf). The number of aphids that stayed in a leaf colony was scored at the 24th hour after leaf colonization. Percent decrease (mean ± SD; n = 120 leaf colonies) in the number of aphids that run away from the leaf colonies was calculated. (b) Total duration of the phloem phase in a four-hour EPG monitoring course. Plants treated as in (a) were colonized by aphids at the fifth day after treatment; uniform aphids were placed on upper sides of the top first expanded leaves. Feeding activities were detected immediately with a four-channel current amplifier system, and total duration of the phloem phase (mean ± SD; n = 20 aphids) was scored. (c) The second-hour EPG record particularly indicating the phloem phase (PP) in WT and an AtPP2-A1-defected mutant. Experiments were the same as in (b). The EPG record represents 20 aphids feeding from 20 plants of WT and the mutant, respectively. (d, e) Reproduction of aphid adults and colonization behaviors of newborn nymphs. Experiments were similar as in (a) and insects were surveyed in five days after colonization of leaves by adults. Reproduction rate was given as the ratio between total number of newborn nymphs and total number of adults on leaf colonies. The population decrease was based on total number of nymphs and the number of nymphs that run away from the leaf colony. Data represent mean ± SD (n = 120 leaf colonies).