Details

Autor(en) / Beteiligte

• Curtis, N. E
• Middlebrooks, M. L
• Schwartz, J. A
• Pierce, S. K

Titel

Kleptoplastic sacoglossan species have very different capacities for plastid maintenance despite utilizing the same algal donors

Ist Teil von

• Symbiosis (Philadelphia, Pa.), 2015, Vol.65 (1), p.23-31

Ort / Verlag

Dordrecht: Springer-Verlag

Erscheinungsjahr

2015

Quelle

SpringerLink

Beschreibungen/Notizen

• The sea slug Elysia clarki sequesters photosynthetically functional chloroplasts from at least a dozen algal species and maintains these plastids for up to 4 months. Elysia papillosa and Placida kingstoni also feed on some of the same, or congeneric species such as Bryopsis plumosa and Penicillus lamourouxii, but cannot maintain plastids longer than 2 weeks. Photosystem II maximum quantum efficiency (ϕIIₑ₋ₘₐₓ) was measured in freshly fed specimens of E. clarki, E. papillosa, and P. kingstoni using pulse amplitude modulated (PAM) fluorescence. The slugs were then immediately starved, and PAM fluorescence measurements continued with starvation until ϕIIₑ₋ₘₐₓreached near 0 or animals expired. Initially, E. clarki fed either P. lamourouxii or B. plumosa had ϕIIₑ₋ₘₐₓvalues that were statistically equivalent. However, as length of starvation increased, ϕIIₑ₋ₘₐₓdecreased differently. After 12 weeks, E. clarki fed B. plumosa had no ϕIIₑ₋ₘₐₓactivity, while those fed P. lamourouxii still had low ϕIIₑ₋ₘₐₓlevels. Freshly fed E. papillosa had ϕIIₑ₋ₘₐₓ > 0.5 initially, which declined over the next 12 days of starvation. Freshly fed P. kingstoni specimens also had ϕIIₑ₋ₘₐₓ > 0.5 immediately, but it rapidly dropped to near 0 over the next 4 h of starvation. Thus, the algal source of sequestered chloroplasts in E. clarki has a minor effect on chloroplast longevity and ϕIIₑ₋ₘₐₓvalues during prolonged starvation. However, among slug species, specific adaptations account for the tremendous variation in the length and functionality of these kleptoplastic associations.