Vascular cambial sucrose metabolism and growth in loblolly pine (Pinus taeda L.) in relation to transplanting stress

Abstract

Sucrose synthase (SS) was the dominant enzyme of sucrose metabolism in both stem and root vascular cambial zone tissues of nursery-grown loblolly pine (Pinus taeda L.) seedlings.Acid invertase (AI) and neutral invertase (NI) activties were generally less than 10% of the SS activity in both tissues.In both cambial tissues, seasonal patterns of SS activity in stem and root cambia paralleled the periodic growth of stems and roots. Stems had high SS activity and growth during summer and early fall.Roots had substantial SS activity and growth during summer and fall, but SS activity and growth were even higher in winter.When seedlings were transplanted, about eight months elapsed before stem and root cambia resumed rates of growth and sucrose metabolism similar to those in control nontransplanted seedlings. Two months after transplanting, root SS was at its lowest, whereas AI activity in transplants was 50% higher than in control nontransplanted seedlings.In stems, SS activity decreased in response to transplanting, whereas AI and NI activities did not change appreciable.

Citation

Sung, Shi-Jean S.; Kormanik, Paul P.; Black, C.C. 1993. Vascular cambial sucrose metabolism and growth in loblolly pine (Pinus taeda L.) in relation to transplanting stress. Tree Physiology 12:243-258.