“This data set explains the hypothesized ‘cyclosis/pressure mechanism’ for microbe expulsion from root hair cells in the rhizophagy cycle. The ‘cyclosis/pressure mechanism’ contends: 1) Intracellular microbes are deposited at the root hair tip by cyclosis in hairs; 2) Pressure builds up behind the tip that expands (stretches) the wall, creating pores; 3) Microbe protoplasts are expelled through the pores as pressure builds due to expansion of the root hair cell; 4) Once outside the root hair microbe cell walls are formed; within root cells reactive oxygen bombardment likely inhibits/denatures microbe cell wall construction enzymes; 5) Nutrient flow in root hairs is toward hair tips based on observations that microbial growth occurs after microbes are expelled from hairs; 6) Previous experiments have shown that root hair elongation stops after all microbes have been expelled from hairs. 7) It may be hypothesized that microbes produce hormones (perhaps auxins) that trigger hair elongation, but this must be proven.”
