J. Phycoi. 15, 154- 162 (1979) DEVELOPMENT OF jANCZEWSKlA lV/ORlMOTOl (CERAl\HALES) ON ITS HOST LAURENCIA NIPPONICA (CERAMIALES, RHODOPHYCEAE) ! Arthur lVI . Nonomura Lab.:>ratnrlo de Flcologl Department of Bot an y, Univers ity of Ca lifo rn ia, Berkeley, California 94720 , D~pert ~H~1 e rrto.de Biolog ' F acu t.t a-d de C len c 11::1 ABSTRACT o AM Janczewskia morimotoi Tokida was successfully cul­ (Co urt 1977) show no evid en ce for uptake of host tured[rom spore to reproductive maturity on its host Lau­ phot osynthate by mature J. gardne ri Setchell. Court rencia nipponica Yamada. Th e spore penetrates the host (1977), the refore, suggests that J. ga rdne ri is an ob­ without requirementJar wound or abrasion sites, gTowing ligat e ep iphy te rather th an a h oloparasite. This between host cortical cell , and deueloping a superficial and viewpoint doe s not con sider th e possible tr ace re­ an endophytic system simultaneously. During the juvenile quirements for host substances othe r than ph oto­ period, when the parasite is nonpigmented, it difJerentiates syntha te o r host metabolit es in early parasite devel­ a cortex and the proliferating endophyticfilaments enlarge op me nt. causing a displacement of layers of host cells into the para­ Although investigations have been made on the sitic tissue. H ost cells contacted by cells oj the parasite ex­ pen et rati on of J. uerrucaejormis Solms-Laubach into hibit increased wall thickness, cytoplasmic density and ves­ th e h ost Laurencia obtu sa (H udson) Lamouroux icle[ormation. Pit connections between host and parasite (Solrn s-Laubach 1877, Falk enberg] 90 ] , Feldmann cells were rarely observed whereas penetration oj host cell and Feldmann] 958), int erpretati ons of its devel­ walls was seen commonly. As the parasite increases in size, op me nt co nflict, and no one has observed the entire its cells become pigmented evenly throughout the cortex and d evelopment. In the onl y previou s study of Jan­ host cell; show less obvious reactions to the parasite. At this czeushia infectivity, Feldmann a nd Feld rnann (1958) same time, the parasite deoelops branches and reproductive were un abl e to follow a nd cor rec tly int erpret devel­ structures. H ost plant segments less than 3 cm long Jailed o pme nt afte r rhizoid penet rati on. to gruw when injected with spores o] the parasite whereas The major objectives of th is inv estigation are to longer segments were not significantly affected by the par­ describ e th e entire development of janczewskia mo­ asite. In the absence oj the host, the parasite cannot com­ rimotoi T okida from spore infection to reproductive plete its development. Although J. morimotoi is well pig­ matu rity a nd to observe the effec ts of infection on mented at maturity, the absence oj pigmentation in the the gro wth of the host, Laurencia nipponica Yamada, juvenile stage, penetration of host cells, and eJJect on host in cu ltu re . J. morimotoi is d ist ributed from Kaiba-to, growth in culture strongly suggest that it is parasitic dur­ Saghalien southward th rou gh the T ohoku region of ing at least its early devel opment . H onshu, J apan . Its general habit a nd reproductive a natomy were fir st described by T okida (1947). This Key index words: Ceramiales; endophyte, J an czewskia; parasitic red alga is light to deep burgundy in color, J anczewskia ; Laurencia ; life history, J anczewskia; hemispherical to glob ose, up to 1,5 em diam a nd parasitic algae; parasite, Janczewskia; Rhodophyta can be a solid tubercle in late su m me r or have nu­ merous radiating free branch es in winter and Sin ce [ anc zeioskia was first described by Solms­ sp rIng . Laubach (1877 ), its characterization as a parasitic red alga has remained uncertain because of a lack MATERIALS AND M ETHO DS of understanding of its physiology, d evelopment Between March and July 1976 , plants of Laurencia nipponica and relati onship to its hosts. Eddelbuttel (19 10) con­ fre e of [ anczru.skia morimotoi and mos t epiphytes were collected sidered only Choreocolax and H arueyella to be defi­ fr om lower int ert idal roc ks at Hokk aido University Marine Lab­ nitely parasitic becau se evidence from cystoca rp de­ o ra tories at Mu ro ran an d Osh oro , J ap an. j. morimo toi does not ve lo p men t clea r ly d emarcates th ese gene l-a as occu r at Oshoro. and L. nipponica was collected fo r cu lture here se para te taxonomic entities from th eir hosts, a nd as well as at Mu ro ran to d eterrnin e whether d iffe renl host pop­ lack of pigm entat ion and reduced th allu s size indi­ ulat ions re act differently to t he parasite. Between J u ne and Au­ g USl 1976, tetrasporo phytic and carpospo rophytic j. morimotoi cate nutrition al dependence on their hosts. All the gro wing on L. nipponu a were colle cted at Mu roran. Voucher other red algal parasites known at th e time of Ed­ sp ecimens fro m these collections wer e p ressed o r preserved in delbuttel's publication possess plastids and some de­ 5% formalin. Plants for culture were wash ed vigorou sly under gree of pigm entation and, thus, were considered running seawater or in buckets and transpo rted in plastic bags herniparasitic. On the basis of pigme nt ati on, Setch­ for 2-4 h to Hok kaid o U niversity in Sappo ro , Japan. ell (1914) stated th at janczewskia species co uld vary All host and parasi te thall i used fo r cultu re wer e subjected to the following co nd itions: plants were washed in 0.1% sodi um fr om hernipar asitic to holoparasitic. Ph ysiological hypochl or ite in seawater for 30 s and rinsed several lim es in investigati ons u sin g radioacti ve carbo n tracers ste rilized seawater (steamed 0 0' a u roc laved) . Fo r t he first mo nth , isolates we re gr o wn in 0.25-0.50 strength Provasoli's en riche d I A ccepted: 2 / October t 978. seawater medium (McLach lan 1973) at 30-33'1,0 salin ity. Plants 154 j A NCZ E WS KIA iVlOR IMOTOJ 155 No te : Sca le = J m rn in Frcs. 5 & 6 , and 100}.Lm in other figures. FIGs. 1- 8. Attac hment ofjanrU lOShw. morimo loi to La ure ncia nipponica and su bse q ue n t ea rly d e velo p me nt o f th e pa ras ite . FtG. I. [aruznoskia init ial att ach me nt to Lau renrin. FIG. 2. No npigmented co rt ical skirt at th e base (If a pigmented kn o b. FIG. 3. Well d e veloped no n pigmented co rtex with kn ob. FIG. 4 . In itiation of trichob last fo rmation with pale pigm e nta tion. FIG. 5. B ran ch initiat ion. FIG. 6 . Mature thallus with fuJI pigmentatio n. F IG. 7. L auren cia spo reling wit h [ aruze uskia in fect io n at its base (a rro w). FtG. 8 . H ost ge rm ling with an infection (ar row) . were grown at 15 C, 16:8 LD p hotoperiod, a nd 100- 200 lx cool­ Tissue grafts fr om J. mori motoi "ere made o nto L. nipponira in whi te fiu oresce ru illuminati on. Three to five d ro ps of C eO , ( I two ways : a p ica l seg me n ts of j. mo,.imoloi bra nc hes were placed mg/m l) were added to 200 ml cu ltu res as need ed (Mc Lac h lan o n sc ra pe d or una braded host plants; o r , medu lla r )' and co rtica l 1973). During th e second month o f g ro wth , th e isolates were tissu e fr om j. morimotoi was g ra fte d int o inci sions bel ow th e host tra ns ferred to full strength Provasoli's e nriched seawater, 500­ epidermis. 1000 Ix cool-white Ruoresce nt illumination , a nd othe r cu lture For ligh t m in osco p )', seg me n ts of L. nipbonica with J. ", ulimului cond itio ns as given . Cu ltu re media were ch an ged every 3 wk . were fixed in Ka r rio vskv's ( 1965) fixative adj usted to 890 mos M Wh en mature, female tha lli were mix ed with male thalli at a ratio at room tempe ratu re for 2 h, and we re post-fixed in cacod yla te o f ca. 1:4 in 500 m l crystallizing di sh es o n table shakers at 100 buffered J% O sO. at 4 C for 12 h. T hey were dehydrat ed in rpm for 1 wk . A ll oth er cu ltu res we re grown in 200 ml to 400 ml ace to ne a nd embedded in Epon-Araldite m ixtu re No.2 (Mo llen ­ p yrex g lass sto rage vesse ls. ha ue r 1964). Se ctio ns were cut 1.5 }.Lm th ick a nd stained with T o isolate L.