STAY-GREEN and light-harvesting complex II chlorophyll a/b binding protein are involved in albinism of a novel albino tea germplasm ‘Huabai 1’

Abstract ‘Huabai 1’ is a new albino tea germplasm, with high amino acids in its albinism period, however, the albino mechanism remains unknown. To understand the albinism mechanism of ‘Huabai 1’, molecular-level studies were carried out to reveal the functions of CsLHCII and CsSGR in albinism. In this study, transmission electron microscopy (TEM) observations revealed that albino leaves of ‘Huabai 1’ are more damaged than that of ‘Baiye 1’. CsSGR overexpression in A. thaliana and N. benthamiana indicated that CsSGR is involved in the regulation of leaf albinism, and it may play an important role as a key regulator for the dismantling of photosynthetic chlorophyll - LHCP complexes. Moreover, CsLHCII overexpression promotes leaf regreening. The Yeast two-hybrid (Y2H) screening identified a chloroplast small heat shock protein (CssHSP, XM_028206028.1) which binds to CsSGR and CsLHCII respectively, forming CsSGR-CssHSP-CsLHCII protein complexes that may function in regulating albinism of ‘Huabai 1’.