The development of CRISPR-Cas genome editing technology, notably the Cas9 and Cas12a systems, has significantly advanced biomedical studies and plant research. The Cas9-derived base editors have been effectively utilized for precise C-to-T, A-to-G, and C-to-G base editing in mammalian cells and plants, thanks to the availability of Cas9 nickase. Base editing scope can be further expanded with engineered variants of SpCas9 or other Cas9 orthologs with altered protospacer adjacent motif (PAM) requirements. CRISPR-Cas12a recognizes T-rich PAM, which can further expand the base editing range. However, the absence of an efficient Cas12a nickase presents a challenge in the development of efficient Cas12a-based base editors, necessitating the use of a deactivated Cas12a (dCas12a). Here, we present a detailed protocol for constructing T-DNA vectors using a deactivated Lachnospiraceae bacterium Cas12a (dLbCas12a) with the D156R mutation, coupled with an adenine base editor (ABE), which has demonstrated high efficiency in multiplexed A-to-G base editing in rice.