Nitrogen concentration in plants is normally determined by expensive and time consuming chemical analyses. As an alternative, chlorophyll meter readings and N-NO(3) concentration determination in petiole sap were proposed, but these assays are not always satisfactory. Spectral reflectance values of tomato leaves obtained by visible-near infrared spectrophotometry are reported to be a powerful t...

DIR1 is a lipid transfer protein (LTP) postulated to complex with and/or chaperone a signal(s) to distant leaves during Systemic Acquired Resistance (SAR) in Arabidopsis. DIR1 was detected in phloem sap-enriched petiole exudates collected from wild-type leaves induced for SAR, suggesting that DIR1 gains access to the phloem for movement from the induced leaf. Occasionally the defective in induc...

The tomato (Lycopersicon esculentum cv Ailsa Craig) polygalacturonase genes TAPG1 (LYCes;Pga1;2) and TAPG4 (LYCes;Pga1;5) are abundantly expressed in both abscission zones and the pistils of mature flowers. To further investigate the spatial and temporal expression patterns for these genes, the TAPG gene promoters were ligated to beta-glucuronidase (GUS) reporter genes and transformed into toma...

Endophytic fungi were isolated from healthy leaves of Manilkara bidentata (Sapotaceae) collected in Puerto Rico. One leaf was collected from each of three trees. Four 5 X 20 mm panels were cut from each leaf, surface sterilized, cut into 50 1 X 2 mm pieces, and plated on malt agar. Petioles were cut into ten 1 mm segments. Fungi were isolated from 90%-95% of the leaf pieces and all of the petio...

Veins are the main irrigation system of the leaf lamina and an understanding of the hydraulic architecture of the vein networks is essential for understanding leaf function. However, determination of leaf hydraulic parameters is challenging, because for most leaves the vein system is reticulate, contains a hierarchy of different vein sizes, and consists of leaky conduits. We present a new appro...

We present the leaf anatomy of seven amphibious species of Aeschynomene L. (Papilionoideae, Leguminosae), interpreting their structures and ecological functions, and also, providing information on which their taxonomy can be based, especially of morphologically similar species. We evaluated Aeschynomene americana, A. ciliata, A. evenia, A. denticulata, A. fluminensis, A. rudis and A. sensitiva....

The sedimentaion of amyloplasts in tomato leaf petiole cells, when influenced by gravistimulation, gravistimulation and phytohormone epine, an exogenous source ethylene ethephon for a period 0.25–24 h, was demonstrated. Ethephone significantly slowed down the sedimentation serving as statolytes which correlates with its inhibitory effect on formation gravitropic bending stem.

The hydraulic conductance of the leaf lamina ( K lamina ) substantially constrains whole-plant water transport, but little is known of its association with leaf structure and function. K lamina was measured for sun and shade leaves of six woody temperate species growing in moist soil, and tested for correlation with the prevailing leaf irradiance, and with 22 other leaf traits. K lamina varied ...