Photosynthetic parameters change in Lycopersicon esculentum leaves under nutrient deficiencies

Abstract

Lycopersicon esculentum leaves cultivated hydroponically for 24 and 48 hrs with various specific mineral deficits had their photosynthetic characteristics examined. After 24 hrs of K+, NO3-, and PO42- deficiency, a substantial induction of net photosynthetic rate was observed. The net photosynthetic rate of SO42-, Mg2+, Fe2+, NO3-, Ca2+ and PO42- deficits was significantly induced by the 48 hr exposure. After 24 hrs of deficiencies in SO42-, Mg2+, Fe2+, NO3-, Ca2+ and PO42-, stomata conductance was dramatically increased. Deficiencies in SO42-, Fe2+, NO3-, Ca2+ and PO42- were continuously induced over 48 hrs. After 24 hrs of SO42-, Fe2+, NO3-, Ca2+ and PO42- deficiencies, intercellular CO2 concentration shows a considerable induction. After 48 hrs of K+, SO42-, Mg2+ and NO3-deficits, this behavior remained strongly induced. Water use efficiency considerably decreased in response to these changes after 24 hrs of SO42-, Fe2+, NO3- and PO42- deficiencies and this effect continued after 48 hrs of Mg2+, NO3-, Ca2+ and PO42- deficiencies. Deficits in K+, SO42-, Mg2+, Fe2+, NO3-, Ca2+ and PO42- for 24 hrs dramatically increased transpiration rate, which was modified by those deficiencies. A 48 hr exposure to NO3-, Ca2+ and PO42- deficiency dramatically increased the transpiration rate. After 48 hrs, an SO42- deficit drastically decreased the transpiration rate. The findings indicate that after a short term of exposure, it may be possible to diagnose a specific mineral shortage and determine which mineral influenced the parameters of photosynthesis in such a way that the selected parameters responded in a manner that was consistent with the duration of exposure.