This book aims to explain recent developments in Rational Extended Thermodynamics (RET), in particular those that have occurred since the publication of the book Rational Extended Thermodynamics, Second Edition (Springer, New York, 1998) by Ingo Müller and Tommaso Ruggeri. RET is a phenomenological field theory capable of describing nonequilibrium phenomena with steep gradients and rapid changes in space-time out of local equilibrium. Classical thermodynamics of irreversible processes (TIP) relies essentially on the assumption of local equilibrium. Therefore, the validity range of RET is wider than that of TIP. Moreover, RET can predict the finite speed of disturbances because its basic system of field equations is hyperbolic. In contrast, TIP predicts the infinite speed of disturbances because of its parabolic character, which is fatal in a relativistic framework. RET was strongly motivated by-and is in perfect agreement with-the kinetic theory, in particular, the system of moment equations derived from the Boltzmann equation. In RET, the differential system is closed by the universal principles: the objectivity principle, the entropy principle, and the principle of causality and stability. This permits an intimate connection between RET and the mathematical theory of hyperbolic systems with convex extension (symmetric systems). It is, therefore, possible to give a qualitative analysis, and the Cauchy problem is well posed. For example, a well-known theory of viscous heat-conducting fluids based on TIP is the classical Navier-Stokes-Fourier theory with five independent field variables: the mass density, the velocity and the temperature. On the other hand, RET adopts more independent field variables by incorporating nonequilibrium variables such as viscous stress and heat flux into the theory. The limitation of the previous RET is, however, that its validity range has been restricted to rarefied monatomic gases. The present book presents the recent results that have overcome this limitation, that is, the results concerned with polyatomic gases, moderately dense gases, and mixtures of gases with multi-temperature. vii

Inductive cell-cell interactions are essential for controlling cell fate determination in both plants and animals; however, the chemical basis of inductive signals in plants remains little understood. A proteoglycan-like factor named xylogen mediates local and inductive cell-cell interactions required for xylem differentiation in Zinnia cells cultured in vitro. Here we describe the purification of xylogen and cloning of its complementary DNA, and present evidence for its role in planta. The polypeptide backbone of xylogen is a hybrid-type molecule with properties of both arabinogalactan proteins and nonspecific lipid-transfer proteins. Xylogen predominantly accumulates in the meristem, procambium and xylem. In the xylem, xylogen has a polar localization in the cell walls of differentiating tracheary elements. Double knockouts of Arabidopsis lacking both genes that encode xylogen proteins show defects in vascular development: discontinuous veins, improperly interconnected vessel elements and simplified venation. Our results suggest that the polar secretion of xylogen draws neighbouring cells into the pathway of vascular differentiation to direct continuous vascular development, thereby identifying a molecule that mediates an inductive cell-cell interaction involved in plant tissue differentiation.

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domains: a BAR (BIN/amphiphysin/RVS) domain, a pleckstrin homology (PH) domain, an ARF-GAP domain and an ankyrin (ANK)-repeat domain. Recombinant VAN3protein showed GTPase-activating activity and a specific affinity for phosphatidylinositols. This protein can selfassociate through the N-terminal BAR domain in the yeast two-hybrid system. Subcellular localization analysis by double staining for Venus-tagged VAN3 and several greenfluorescent-protein-tagged intracellular markers indicated that VAN3 is located in a subpopulation of the trans-Golgi network (TGN). Our results indicate that the expression of this gene is induced by auxin and positively regulated by VAN3 itself, and that a specific ACAP type of ARF-GAP functions in vein pattern formation by regulating auxin signaling via a TGN-mediated vesicle transport system.

UV radiation induces two major classes of pyrimidine dimers: the pyrimidine [6-4] pyrimidone photoproduct (6-4 product) and the cyclobutane pyrimidine dimer (CPD). Many organisms produce enzymes, termed photolyases, that specifically bind to these damage products and split them via a UV-A/blue light-dependent mechanism, thereby reversing the damage. These photolyases are specific for either CPDs or 6-4 products. A gene that expresses a protein with 6-4 photolyase activity in vitro was recently cloned from Drosophila melanogaster and Xenopus laevis. We report here the isolation of a homolog of this gene, cloned on the basis of sequence similarity, from the higher plant Arabidopsis thaliana. This cloned gene produces a protein with 6-4 photolyase activity when expressed in Escherichia coli. We also find that a previously described mutant of Arabidopsis (uvr3) that is defective in photoreactivation of 6-4 products carries a nonsense mutation in this 6-4 photolyase homolog. We have therefore termed this gene UVR3. Although homologs of this gene have previously been shown to produce a functional 6-4 photolyase when expressed in heterologous systems, this is the first demonstration of a requirement for this gene for photoreactivation of 6-4 products in vivo.

When cultured on media containing the plant growth regulator auxin,hypocotyl explants of Arabidopsis thaliana generate adventitious roots. As a first step to investigate the genetic basis of adventitious organogenesis in plants, we isolated nine temperature-sensitive mutants defective in various stages in the formation of adventitious roots: five root initiation defective(rid1 to rid5) mutants failed to initiate the formation of root primordia; in one root primordium defective (rpd1)mutant, the development of root primordia was arrested; three root growth defective (rgd1, rgd2, and rgd3) mutants were defective in root growth after the establishment of the root apical meristem. The temperature sensitivity of callus formation and lateral root formation revealed further distinctions between the isolated mutants. The rid1mutant was specifically defective in the reinitiation of cell proliferation from hypocotyl explants, while the rid2 mutant was also defective in the reinitiation of cell proliferation from root explants. These two mutants also exhibited abnormalities in the formation of the root apical meristem when lateral roots were induced at the restrictive temperature. The rgd1and rgd2 mutants were deficient in root and callus growth, whereas the rgd3 mutation specifically affected root growth. The rid5 mutant required higher auxin concentrations for rooting at the restrictive temperature, implying a deficiency in auxin signaling. The rid5 phenotype was found to result from a mutation in the MOR1/GEM1 gene encoding a microtubule-associated protein. These findings about the rid5 mutant suggest a possible function of the microtubule system in auxin response.

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We describe the isolation and characterization of cDNAs encoding two DNases that may be involved in the programmed death of plant cells: a 35-kDa nuclease of barley, which had been reported to be secreted from the aleurone layer into the endosperm during germination and may be responsible for the digestion of nuclear DNA in the course of degradation (cell death) of endosperm, and a 43-kDa nuclease of zinnia, which appears transiently in association with differentiation to tracheary elements and is likely to participate in the autolysis at the final step of the differentiation. Genes for these nucleases of barley and zinnia were designated BEN1 and ZEN1, respectively. The amino acid sequence of BEN1 protein deduced from the nucleotide sequence of BEN1 cDNA consisted of 288 residues with a putative signal sequence of 23 residues. RNA gel blot analysis revealed that BEN1 mRNA increased in the embryo-less half seeds of barley in response to the application of gibberellic acid. The deduced amino acid sequence of ZEN1 protein consisted of 303 residues with a putative signal sequence of 25 residues. Temporal accumulation of ZEN1 mRNA was detected during transdifferentiation of zinnia mesophyll cells into tracheary elements. Significant similarities were found among the amino acid sequences of BEN1, ZEN1, nuclease S1 from Aspergillus oryzae, and two other S1-type nucleases.z 1998 Federation of European Biochemical Societies.