G.Zellnie, E.Bermadinger, M.Gailhofer, D.Grill Karl·Franzens·Univesitit Graz
Department of Plant Physiology, Schubertstr. 5 1, A ·80 10 Graz, AUSTRIA
ABSTRACT
Spruce needles were collected from dif·
ferent sea-levels in· alpine areas of Austria.
where inversion ·layers often occur. The spru · ces from higher sea-levels show ultrastructu · ral alterations, which rather indicate a photo·
oxidative stress. whereas the characteristic ul·
trastructural changes in the chloroplasts of the samples from lower sea-levels (valley near) are due to SO2.
INTRODUCTION
One· and two/three-years old needles of spruce (Picea abies (L.)Karst.) were col·
lected in a SO2·emission area (900 m above sea level), an area with new -type forest damage ( 1 000 m as.l) and a clean air area ( 1 200 m as.l). The investigations were performed with the transmissions·
(TEM) and the scanning (SEM) electron ·micro·
scope.
RESULTS AND DISCUSSION
In one· and two·years·old green need·
les from the SO2 emissions area, distinct changes are detectable in chloroplasts of mesophyll·cells. Thus, already chloroplasts of first ·year needles show. above clear changes of the shape. also an enlargement of the in·
trathylaloidal space and inhomogeneously stained plastoglobuli. In second ·year needles besides that the plastoglobuli·number respec
tively ·size increase the plastoglobuli get lightened in a charakteristic manner (Fig. I).
This symptom -combination is still unknown, although there are some other investigations that deal with ultrastructural alterations caused by sulfur ·emissions (SOIKKELI 198 1 , MIYAKE e t al 1984). Besides the well known lightening of the plastogobuli, there is a considerably variation of ultrastructural alterations in the chloroplasts caused by sul·
fur. The surface wax of one·year·old and even more that of two·years·old needles shows symptoms of severe destruction. The
wax rodlets in the stomatal antechamber fuse and the crystalline structure gets Jost (Fll.5) In extreme cases the stomata becnme occluded by a flat and solid wax plug;
the surface gets bare and does not show aystaWne waxrods at all (Flg.6) This well known symptoms caused by SO2 (HUT · TUNEN & LAINE 1983, RIDING &
PERCY 1985, GRILL et al 1987) coincide with the macrosa,pic appearance of the trees: Trees with heavy shedding of the needles also show dramatic wax destructions (GRILL et al 1987}
The "new type" damaged samples were taken from an inversion zone 1000 m above sea level; in this area SO2 is a pollutant of only minor importance. The ap·
pearing alterations in the chloroplasts ue clearly distinguishable from SO2.damaged ("classical") ones. Already one·year·old, areen needles show alterations in the chloroplasts, which manifest in thylakoid enlargements and/or abnormalities in the stroma (Fig.2). Yel·
lowed needles of the same age show al·
ready a reduced thylakoidsystem and large starch grains in the chloroplasts. In three·
years-old green needles an accumulation of plastoglobuli as well as a strong reduction of the thylakoidsystem and an accumulation of starch takes place (Fig.3} In three-years·
old green needles such damages occur even to a larger extent. The unspecific reactions of the samples of this areas indicate a photooxldative stress. Similar ultrastructural al·
terations are reported by SUTINEN 1 987 with green and yellowed needles from Taunus. Accumulation of starch after the in · fluena of SO2 + 0 3 (fumigation experi·
ments) are reported also by KOPPERS &
BLEND 1987.
But also the chloroplasts of one· and three·yeus·old needles of the "clean air area" are not unetrected. W hile in one-year·
old needles choroplasts are found with sporadicaly swollen thylakoids and a slightly increased plastoglobuli number (Fig.4). three·
years-old needles show already a distinct in·
crease of the plastoglobuli number and altera·
lions in the stroma. Similar damage was seen with �-influenced bean leaves (FIS·
CHER 1987) and spruce needles (ZELLNIG et al 1987}
The epicuticular wax of "new·type·
damaaed", strongly yellowed needles as well
as
the wax of needles from the clean air area does not show signs of stress influence exceeding the normal ageing process. Even two·years·old needles have still uninfluenced wax rodlets on the sourrounding area of the stomata and in the stomata! antechamber (Fig.7); the an·techamber wax forms a very dense but porous meshwork consisting of intact wax rods (Ffa.8) (compare also BERMADINGER et al 1988}
CONCLUSIONS
"SOi" damaged needles show charac·
teristic ultrastructural changes in chloroplasts. These can be clearly distin · guished from the structural changes in
"new type" damaged needles; even in needles from "clean air" areas such destruc·
lions of the ultrastructure of chloroplasts are detectable. On the contrary REM inves·
tigations revealed obvious modifications of the epicuticular wax only with "SO£' damaged, but not with "new type"
damaged needles or with needles from a
"clean air" area All these damages are a matter of radical ultrastructural changes In chloroplasts, which concern the carbohydrate·
,respectively the lipidmetabolism. The altera·
tlons of the antechamber wax in "SO2"
damaged needles are expected also to in · fluence the gas exchange.
SUMMARY
Spruces from higher elevations were examined with the transmission· and the scanning electron miaoscope. It is possible to distinguish between classical damage caused by SO2 and photooxidative stress.
ZUSAMMENFASSUNG
An Fichten aus hllher gelegenen Gebieten wurden transmissions· und raster·
elektronenmikroskoplsche Untersuchungen durchgefiihrt. Dabei war es moglich zwi·
schen vorwiegend SO2·domlnierten und vor·
wlegend oxidativ domlnierten Schadbildern zu unterscheiden.
554
LITERATURE
BERMADINGER E.. GRILL D.. GOLOB
P,
1988. GeoJournal 1 7.2: 289 · 293. El:.SCHER E.S.
1987. XIV.lnt.Bot.Cong. Berlin.Abstracts p.80. GRILL
D..
PFEIFHOFER H.. HALBWACHS G.. WALTINGER H..128.Z.. Eur.J.For.Path. 17: 246 · 255. HUT · TUNEN
s..
LAINEK.
1983. Ann.Bot.Fen · nici 0: 79 · 86. KOPPERS IC BLIND Q.lmXIV.Int.Bot.Cong.Berlin, Abstracts, p.405. MIYAKE H.. FURUKUW A A.. TOT·
SUKA T.. MAEDA E. 1984. New.Phytol 96: 2 15 228. RIDING R.T.. PERCY K.E. 1985. New Phytol 99: 555 563.
SOIKKELI S. 198 1. Ann.Bot.Fennlci 18: 47 6 1 . SUTINEN S. 1987. Eur.J.For.Path.
1 7: 74 · 85. ZELLNIG G.. GAlLHOFER M .• HA VRANEKW .M. 1987
Eur.J.CellBioL 43, SuppL 1 8, p. 40.
f!&.t
Two·years·old green needle;chloroplast with charakterislic electron · light plastoglobuli (P). Flg.2: One·year ·old green needle; chloroplast with a normal thylaloid system, electron ·dense plastoglobuli (P).
starch (S) and a membrane-free stroma area (arrow) Flg.3: Three·years ·old green needle; chloroplasts with a few thylakoids, a strong Increased number of plastog!obuh (P) and starch (S). Fig.4: One ·year ·old green needle; chloroplast with a few partial·
ly swollen thylakoids (arrows). a few (some) electron ·dense plastoglobuli (P) and a membrane free stroma area (star). Fig.5:
Two·years·old, stressed needle; part of the antechamber wax; the wax rodlets are fused, the aystalline structur is lost; scale 1,68 ,um. Fig.6: Two·years·old, severly stressed needle; the stomata are covered by an amorphous wax layer. the surfaai is bare; scale .. 16,8 ,um. Fig.7: Two-years·
old yellowed needle; the wax structures on the surface and in the stomata! an · techamber are uneffected; scale • 16,8 ,um. Fig.8: One·year·old needle; the sur · face and the stomata! antechamber (V) is densly covered with aystalline wax, that does not show any alterations; scale = 4,2
1
um.
This work was supported by the Bundes·
mlnlsterlum fiir W lssenschaft und Forschung; the SEM ·studies were per · formed at the Zentrum fiir Elektronenmik · roskople, Graz.
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