Protocol for evaluating seedling greening capacity during dark-to-light transition

We present a protocol to evaluate greening capacity in etiolated Arabidopsis seedlings during the critical dark-to-light transition. We describe steps for sample preparation and sowing and then detail procedures for quantifying protochlorophyllide accumulation in darkness, the greening rate upon illumination, and reactive oxygen species levels as an indicator of photo-oxidative stress. This protocol can be used for screening and phenotypic quantification across genetic backgrounds. For complete details of this protocol, please refer to Zhong et al.¹ and Zhong et al.².