Defective photosynthetic adaptation mechanism in winter restricts the introduction of overwintering plant to high latitudes

Abstract

Because of the need for agriculture and landscaping, many overwintering evergreen and biennial species that maintain green leaves over winter were introduced to higher latitudes. The green leaves of introduced overwintering species have to withstand a harsher winter, especially lower temperature, than in their native region of origin. Although the responses and adaptability of photosynthetic apparatus to winter conditions in native overwintering species were widely studied, the experimental results on the introduced overwintering species are very limited. Here, the photosynthetic adaptability during winter was analyzed in two native overwintering species, pine (woody plants), winter wheat (herb), and two introduced overwintering species, bamboo (woody plants), lilyturf (herb). The native species exhibited higher capacity for photosynthetic CO2 fixation and lower susceptibility for photoinhibition than introduced species during winter. Photosynthesis related proteins, such as PsbA, PsaA, Rubisco and Lhcb1, were marginally affected in native species, but significantly degraded in introduced species during winter. More interestingly, the PSII photoinhibition was mainly caused by up-regulation of photoprotection mechanism, non-photochemical quenching, in native species, but by photodamage in introduced species. This study indicates that the growth and survival of introduced overwintering species is limited by their photosynthetic adaptability to the harsher winter conditions at high latitudes.