(a) ATHB15 mRNA cleavage in N. benthamiana. Total RNAs were extracted from plants without any vector constructs (1), with pBI121 control alone (2), with pBI121 + miR166 vector (3), with pBI121 + ATHB15 vector (4), with pBI121 + ATHB15 vector + miR166 vector (5), with pBI121 + mATHB15 vector (6), and with pBI121 + mATHB15 vector + miR166 vector (7). RNA gel blots were probed with the 5′-end cleavage fragment of ATHB15. The arrow marks the full-size mRNA, and the arrowhead the 5′-end cleavage product.
(b) ATHB15 mRNA cleavage in wheat germ extract. A 5′-end labeled ATHB15- specific RNA was used in the assay.
(c) 5′-RACE to determine the cleavage site in Arabidopsis. The arrow in the diagram marks the cleavage site. The number refers to that of independent clones with the 5′-end as determined.