Yingjuan Su

Conflicts of Interest The authors declare no conflicts of interest. Data Availability Statement The data that support the findings of this study are available from the corresponding author upon reasonable request. References , , and . 2020. “How Does Foreign Direct Investment Contribute to Sustainable Development Goals? Evidence From African Countries.” Journal of Cleaner Production 245: 118823. 2021.

1 INTRODUCTION Epigenetics emphasizes the potential of chemical tags on DNA (e.g., DNA methylation) to modulate gene expression in response to environmental stimuli without changes in the underlying DNA sequence (Jablonka & Raz, 2009; Richards, 2006; Verhoeven et al., 2016). It is also known that epigenetic information based on DNA methylation or chromatin modification could be stably inherited across generations (Heard & Martienssen, 2014; Verhoeven et al., 2010).

1. Introduction Chloroplasts originated from cyanobacteria that invaded or were engulfed by heterotrophic host cells (eukaryotic protozoa) around 1.5 billion years ago, giving rise to the “endosymbiosis” theory [1]. During the early stages of endosymbiogenesis, most cyanobacterial genes were lost or transferred to the nucleus of the host cell. Simultaneously, certain host genes acquired precursor sequences, facilitating their transport to the organelles [2].