Manganese nutrition of Nicotiana tabacum L. in relation to multiplication of tobacco mosaic virus

Abstract

The influence of manganese nutrition of tobacco was studied in relation to multiplication of tobacco mosaic virus. Plants grown in water culture solutions containing various levels of manganese responded with a gradient of growth and deficiency symptoms characteristic of this element. Inoculation of 2 basal leaves of a plant when deficiency symptoms were established resulted in decreased growth at all levels of manganese. Intensity of mosaic symptoms was reduced with decreased levels of manganese. Virus infection of deficient plants reduced the deficiency chlorosis of apical leaves. Manganese-deficient tissue had a greater wet weight and a lower dry weight than normal tissue. Leaf thickness and cell size of manganese-deficient tissue were greater than normal. Total nitrogen of manganese-deficient tissue was greatly reduced. Virus concentration in manganese-deficient tissue reached a higher level than in normal tissue when samples were assayed on either a wet or dry weight basis by either ultraviolet absorption or local lesion assays. This was true for systemically infected plants and for inoculated leaf discs. Virus synthesis apparently occurs at a greater rate in chlorotic, manganese-deficient tissue than in normal tissue, indicating an independence of virus synthesis with regard to manganese-controlled enzyme systems.