Changes in structure of red pepper (Capsicum annuum L.) seedlings shoots under aluminum stress conditions

Agata Konarska

doi:10.5586/aa.2007.010

Abstract

The seedlings of the red pepper (Capsicum annuum L.) cv. Trapez grown in water culture for a period of 14 days with Al (0, 10, 20 and 40 mg·dm-3 AlCl3·6 H2O). Some morphological and anatomical features of red pepper shoots were analyzed. Reduction in height and diameter of stems as well as decrease in fresh mass of shoots were observed after Al-treatment. In the hypocotyl the thickness of cortex parenchyma layer and the size of their cells were reduced. The aluminum treatment resulted in the increased in thickness of the epidermis outer cell wall. Under Al stress in the cotrex and the central cylinder parenchyma cells were present numerous enlarge plastids which contained large grains of starch and dark little bodies which were possible aluminum deposits. They weren`t observed in control seedlings.

Highlights

The toxicity of aluminum is a factor which is commonly recognised as a factor limiting plant growth and yielding
With the increased concentration of aluminium, the height of the plants was reduced from 28.7% up to 38.9%, what was accompanied by the shortening of the length of both the hypocotyl and, to a larger degree, the epicotyl
Epidermis cells of the hypocotyl of pepper from the control object observed in SEM were of rectangular shape and they were elongated parallel to the vertical axis of the organ

Summary

Introduction

The toxicity of aluminum is a factor which is commonly recognised as a factor limiting plant growth and yielding. The excess of mobile forms of this metal in the substratum affects especially underground organs of the plant, mainly roots, by inhibiting their elongation growth, causing numerous deformations and damages, as well as the limitation of water intake (Bennet and Steward , 1999; Budikova and Mistrik , 1999; Konarska , 2005). Most researchers are of opinion that changes observed in such cases correspond to nutrient and water deficiency symptoms which may accompany the excess of aluminium in the substratum (Janhunen et al, 1995; Rufyikiri et al, 2001). In spite of the fact that most toxic ions of this metal taken in by the plant are immobilised in roots (Borowski , 1999; Lidon et al, 1999), a part of them can migrate to the above-ground portion in sensitive or aluminium-loving plants. Aluminium deposits are observed in leaves and accumulated in their peripheral portions, i.e. in cell walls of the upper epidermis, in particular in the cuticle layer or in the walls of palisade parenchyma cells (Garrec and Renard , 1996; S h e n and M a , 2001)

Results

Discussion

Conclusion