Figure 6.

Antisense perturbation of PSiP function. (A) Northern analysis showing positive hybridization of PSiP/DIG labeled with 25, 10, and 5 μg of total RNA from pollen of A. umbellatus. (B) Control cell, germinated in liquid medium supplemented with 15 μg⋅ml⁻¹ of cytofectin in the absence of antisense probes. (C–G) Effect of ODNs after 3 h of germination. A clear perturbation of tip growth led to abnormal morphology. The examples were chosen from a gallery of images representative of altered behavior. C and D germinated in DETEKEE-antisense; E–G germinated in LRVLDLS-antisense. (H) Recovery of normal tip morphology in an ODN-treated cell induced by 20 μM dibutyryl cAMP; arrow indicates addition of cAMP (≈3 h and 30 min after germination). (I) Dot-blot hybridization of 5 μg of total RNA from pollen of A. umbellatus probed with different DIG-labeled ODNs. The hybridization signals correlated with the antisense effect observed in the germinating cells. Estimates from countings were +++, more than 70% of cells perturbed; ++, between 40 and 70%; +, less than 40%; and −, less than 10% (which can be considered normal for germination periods longer than 3 h).