A reporter for noninvasively monitoring gene expression and plant transformation

Abstract

Reporters have been widely used to visualize gene expression, protein localization, and other cellular activities, but the commonly used reporters require special equipment, expensive chemicals, or invasive treatments. Here, we construct a new reporter RUBY that converts tyrosine to vividly red betalain, which is clearly visible to naked eyes without the need of using special equipment or chemical treatments. We show that RUBY can be used to noninvasively monitor gene expression in plants. Furthermore, we show that RUBY is an effective selection marker for transformation events in both rice and Arabidopsis. The new reporter will be especially useful for monitoring cellular activities in large crop plants such as a fruit tree under field conditions and for observing transformation and gene expression in tissue culture under sterile conditions.

Seeing is believing: a visualization toolbox to enhance selection efficiency in maize genome editing

“…This set of tools makes the positive selection of transgenic events cost‐effective and rapid (Figure 1k). The ability to accurately visualize fluorescence with the naked eye is the major advantage of the system compared with the use of other fluorescent markers, such as GFP, RFP, or mCherry, and anthocyanin or betalain pigment‐based systems that colour the whole plant (He et al, 2020; He and Zhao, 2020), the fluorescence‐derived tool is suitable for both positive and negative selection, and because it does not affect plant development or seed germination, it is also suitable for other crops. ViMeBox could also be combined with other emerging technologies.…”

Biosensors: A Sneak Peek into Plant Cell’s Immunity

“…A similar approach, avoiding exogenous substrate application, was explored in the reporter RUBY which produces red betalain pigment. The three enzymes that cooperate in its biosynthetic pathway from tyrosine were expressed under the control of various promoters in A. thaliana and were co-translationally separated due to the addition of 2A self-cleaving peptide [ 163 ].…”

Biosensors: A Sneak Peek into Plant Cell’s Immunity

“…Similar approach, avoiding exogenous substrate application was explored in the reporter RUBY which produces red betalain pigment. The three enzymes that cooperate in its biosynthetic pathway from tyrosine were expressed under the control of various promoters in A. thaliana and were co-translationally separated due to the addition of 2A self-cleaving peptide [162].…”