ABSTRACT

I. INTRODUCTION It is well established that trace metals are indispensable for physiological and biochemical processes in plants. For instance, in plants growing in a Zn-deficient medium the stem fails to elongate and there is a marked reduction of shoot fresh weight [1,2]. Resupply with Zn stimulates growth [1]. At the biochemical level, various metals are involved in the structure and the biological activity of many proteins (Table 1). Other molecules such as chlorophylls require Mg for their structure and function.