MODELING OF THE UPTAKE, FLOW AND UTILIZATION OF C, N AND H2O WITHIN WHOLE PLANTS OF RICINUS-COMMUNIS L BASED ON EMPIRICAL-DATA

被引:49
作者
JESCHKE, WD [1 ]
PATE, JS [1 ]
机构
[1] UNIV WURZBURG,LEHRSTUHL BOT 1,W-8700 WURZBURG,GERMANY
关键词
RICINUS-COMMUNIS; CARBON; NITROGEN; WATER; PARTITIONING; XYLEM TRANSPORT; PHLOEM TRANSPORT; XYLEM-PHLOEM TRANSFER; XYLEM-XYLEM TRANSFER;
D O I
10.1016/S0176-1617(11)80322-6
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
An empirically based modelling technique was used to quantitatively depict uptake, flow and utilization of C, N and H2O for a 9 day period in mid vegetative growth of NO3-fed caster bean (Ricinus communis L.) exposed to a mean salinity stress of 128 mol m-3 NaCl. The models incorporated data on C:N weight ratios of solutes of phloem sap and pressure-induced xylem exudates of leaves, stem internodes and petioles, net increments or losses of C, N and H2O in plant parts, transpirational losses of shoot organs and respiratory losses of C from shoot parts and root. A computational technique was developed to assess the extent of xylem to phloem transfer of C and N within internally sited organs (stem segments and petioles) in addition to traffic of C and N through these organs to terminal organs (root, shoot apex and leaves). Molar ratios of inputs of H2O:C:N were 4803:22:1. Half of the net daytime photosynthetic gain of C by the shoot was translocated initially to the root, 33% was lost in root respiration, 17% in shoot night respiration, 8% cycled through the root system and 40% was finally incorporated into shoot dry matter, 10% into root dry matter. The corresponding N budget showed 93% initial transfer in xylem from root to leaf laminae, 32% backflow in phloem from shoot to root and 15% cycled through the root. The water budget involved a 98% loss in transpiration, 2% incorporation into tissues and 2% commitment to phloem transport. Xylem to phloem exchanges of C and N in shoot mostly involved transfer from xylem to phloem. The models predicted a steep upward gradient in decreasing water use efficiency with leaf age, due principally to poor CO2 fixation in relation to water loss by youngest leaves. Comparison of fluxes of N and H2O between stem internode segments with those passing out to leaves indicated progressive lateral abstraction of N from leaf traces serving lower leaves and subsequent passage of this N to the xylem of cauline traces serving upper regions of the shoot. Data were compared with earlier obtained information on C, N and H2O partitioning in nodulated white lupin (Lupinus albus L.).
引用
收藏
页码:488 / 498
页数:11
相关论文
共 20 条
[1]   NITROGEN-CONTAINING COMPOUNDS IN SHOOT SYSTEM OF PISUM ARVENSE L. I. AMINO COMPOUNDS IN BLEEDING SAPS FROM PETIOLES [J].
BRENNAN, H ;
PATE, JS ;
WALLACE, W .
ANNALS OF BOTANY, 1964, 28 (112) :527-&
[2]   CHEMICAL COMPOSITION OF RICINUS PHLOEM EXUDATE [J].
HALL, SM ;
BAKER, DA .
PLANTA, 1972, 106 (02) :131-&
[3]   PARTITIONING OF K+, NA+, MG++, AND CA++ THROUGH XYLEM AND PHLOEM TO COMPONENT ORGANS OF NODULATED WHITE LUPIN UNDER MILD SALINITY [J].
JESCHKE, WD ;
PATE, JS ;
ATKINS, CA .
JOURNAL OF PLANT PHYSIOLOGY, 1987, 128 (1-2) :77-93
[4]  
JESCHKE WD, 1986, J PLANT PHYSIOL, V124, P257
[5]  
JESCHKE WD, 1988, J PLANT PHYSIOL, V132, P45
[6]   ION CIRCULATION VIA PHLOEM AND XYLEM BETWEEN ROOT AND SHOOT OF NODULATED WHITE LUPIN [J].
JESCHKE, WD ;
ATKINS, CA ;
PATE, JS .
JOURNAL OF PLANT PHYSIOLOGY, 1985, 117 (04) :319-330
[7]   PARTITIONING OF CARBON AND NITROGEN AND THE NUTRITION OF ROOT AND SHOOT APEX IN A NODULATED LEGUME [J].
LAYZELL, DB ;
PATE, JS ;
ATKINS, CA ;
CANVIN, DT .
PLANT PHYSIOLOGY, 1981, 67 (01) :30-36
[8]   ECONOMY OF PHOTOSYNTHATE USE IN NITROGEN-FIXING LEGUME NODULES - OBSERVATIONS ON 2 CONTRASTING SYMBIOSES [J].
LAYZELL, DB ;
RAINBIRD, RM ;
ATKINS, CA ;
PATE, JS .
PLANT PHYSIOLOGY, 1979, 64 (05) :888-891
[9]   PHLOEM TRANSPORT IN RICINUS - CONCENTRATION GRADIENTS BETWEEN SOURCE AND SINK [J].
MILBURN, JA .
PLANTA, 1974, 117 (04) :303-319
[10]   ANALYSIS OF RESPONSE IN PHLOEM EXUDATION ON APPLICATION OF MASSAGE TO RICINUS [J].
MILBURN, JA .
PLANTA, 1971, 100 (02) :143-&