Responses of Two Apiaceae Species to Direct Iron Deficiency

The aim of this study was to investigate the morphological and physiological responses of Petroselinum crispum and Apium graveolens to iron deficiency. Seedlings of both species were cultivated in continuously aerated nutrient solution with or without 48.8µM Fe during one month. Score chlorosis, growth parameters, chlorophyll content, acidification capacity and iron, zinc and copper levels, were measured. The results showed that growth of both species was severely affected by direct iron deficiency. Nevertheless, chlorosis symptoms were more severe in P. crispum, compared to A. graveolens. High chlorosis index and a significant decrease of chlorophyll content were registered in P. crispum. In addition, shoot length and whole plant biomass production were affected by iron deficiency in both species. The lower reduction was observed in Fe-deficient plants of A. graveolens. However, the later specie registered the highest root length. Moreover, a capacity of root acidification due to a noticeable proton release rate was observed with A. graveolens. Although grown under Fe deficiency conditions, these specie was able to increase their shoot iron use efficiency. Furthermore, Fe deficiency led to a significant accumulation of zinc in leaves of both species while copper accumulation was only noted in P.crispum roots. The capacity of A. graveloens to maintain plant growth and to preserve adequate chlorophyll synthesis under iron-limiting conditions is related to its better Fe-use efficiency, in addition to its high acidification and root reducing capacities. This allows us to suggest that A. graveolens is more effective to overcome iron deficiency than P. crispum.