Appearance of a new leaf rot disease on common ice plant

An unknown disease abruptly appeared on hydroponic cultures of common ice plant (Mesembryanthemum crystallinum) in the greenhouse, causing catastrophic damage. Although the symptoms of the plant were unlike typical Botrytis lesions on leaves and stems of other plants, fungi isolated from the necrotic lesions on the plant were similar to genus Botrytis in terms of conidial shape, colony color and nature. A representative isolate, Ice-2, caused similar symptoms on the host plants after inoculation with conidia, and the same fungus was isolated from the lesions. The conidia and conidiophores of Ice-2 were morphologically similar to those of B. cinerea but not to those of B. allii, B. fabae or B. squamosa. The tested Botrytis fungi grew at temperatures between 5 and 30°C. Ice-2 grew faster than the others at the lower end of the temperature range. Ice-2 was also more virulent than B. cinerea (Bay-1) in artificial inoculations, especially on common ice plant leaves. The glyceraldehyde-3-phosphate dehydrogenase gene (G3PDH) sequence of Ice-2 was determined and compared with those from four Botrytis species. The gene sequence of Ice-2 appeared to be identical to that of B. cinerea. In leaf tests on common ice plant and kidney bean, the diseases caused by Ice-2 and Bay-1 were controlled equally well by the primary Botrytis fungicides. Based on the results of the present studies, Ice-2 is thought to be Botrytis cinerea Person: Fries.     

Partial cDNA sequence of a relaxin‐like factor (RLF) receptor,LGR8 and possible existence of the RLF ligand‐receptor system in goat testes

Relaxin‐like factor (RLF), also known as insulin‐like factor 3 (INSL3), is produced by testicular Leydig cells, but its specific receptor LGR8 (leucine‐rich repeat family of G‐protein‐coupled receptor 8) has not been identified in goats. This study aimed to identify complementary DNA (cDNA) sequences of goat LGR8, and characterize the expression of both RLF and LGR8 in goat testes by RT‐PCR and immunohistochemistry. Testes were collected from immature (3‐month‐old) and mature (24‐month‐old) Saanen goats, and partial cDNA sequences of the goat homologue of human LGR8 were identified. The sequence encoded a reduced peptide sequence of 167 amino acids, which corresponded to transmembrane regions 2 through 5, followed by the beginning of intracellular loop 3 of human LGR8. Expression of both LGR8 and RLF genes was drastically increased in mature testes compared with immature ones. Although RLF protein was restricted to Leydig cells, LGR8 protein was detected in both Leydig cells and seminiferous epithelial cells (possibly germ cells and Sertoli cells). These results reveal a possible existence of the RLF‐LGR8 ligand‐receptor system within the goat testis, suggesting that RLF may play a role in testicular function through LGR8 on Leydig cells and seminiferous epithelial cells in an autocrine and/or paracrine manner.     

Isolation and expression of five-amino-acid-deleted variant of feline hepatocyte growth factor (HGF) cDNA

Hepatocyte growth factor (HGF) is a pleiotropic cytokine that stimulates a wide array of cellular targets, including hepatocytes and other epithelial cells, melanocytes, endothelial and hematopoietic cells. We have cloned a different form of cDNA, with a deletion of 15 base pairs predicted to result in the loss of 5 amino acids from the first kringle domain. To investigate the biological activity, original and deleted variant of feline HGF cDNAs were transiently expressed in COS-7 cells. Both recombinant feline HGFs showed almost the same dose-response curves in the stimulation of the growth of BNL CL.2 cells (a mouse hepatocyte cell line) and scatter activity of Madin-Darby canine kidney (MDCK) cells. The findings reported here suggest that the deleted variant of feline HGF has almost the same biological activity as the original in terms of the proliferation and scatter activity.     

Accumulation mechanism of γ-aminobutyric acid in tomatoes (Solanum lycopersicum L.) under low O2 with and without CO2

The storage of ripe tomatoes in low-O(2) conditions with and without CO(2) promotes γ-aminobutyric acid (GABA) accumulation. The activities of glutamate decarboxylase (GAD) and α-ketoglutarate-dependent GABA transaminase (GABA-TK) were higher and lower, respectively, following storage under hypoxic (2.4 or 3.5% O(2)) or adjusted aerobic (11% O(2)) conditions compared to the activities in air for 7 days at 25 °C. GAD activity was consistent with the expression level of mRNA for GAD. The GABA concentration in tomatoes stored under hypoxic conditions and adjusted aerobic conditions was 60-90% higher than that when they are stored in air on the same day. These results demonstrate that upregulation of GAD activity and downregulation of GABA-TK activity cause GABA accumulation in tomatoes stored under low-O(2) conditions. Meanwhile, the effect of CO(2) on GABA accumulation is probably minimal.     

Interspecific cytoplasm substitutions of an Indica strain of Oryza sativa L. and O. Glaberrima Steud

Summary To study differential nucleus-cytoplasm interactions between the two cultivated rice species, Oryza sativa and O. glaberrima, cytoplasmic substitution lines were made by using a glaberrima strain (G) and an Indica strain of sativa (S). The G cytoplasm had no adverse effect on pollen development when combined with the nucleus of S. On the other hand, when the S cytoplasm was combined with the G nucleus, the substitution line showed no seed set because of male sterility although the pollen grains were normally stained with I₂-KI solution. A dominant gene derived from S strain seemed to cause anther indehiscence in the substitution line. Further, a restorer gene (Rf _j)from Akebono of Japonica type was effective on pollen restoration in the male sterile line, suggesting that the S cytoplasm is the same as those of Japonica type in terms of a fertility-restoring system.This paper is Genetic studies of speciation in cultivated rice. 4.     

Molecular differentiation,diversity, and folk classification of “sweet” and “bitter” cassava (<Emphasis Type="Italic">Manihot esculenta</Emphasis>) in Caiçara and Caboclo management systems (Brazil)

This study focuses the inter-relationships among the men, the use, and the intra-specific cassava diversity, under the perspective of this crop evolutionary dynamics. The origin, the use and the current local management of varieties with high and low cyanogenic potential are important questions around cassava domestication. We collected 169 local varieties identified as “sweet” or “bitter” cassava by traditional farmers from Atlantic Forest and Amazon (Medium Negro River Basin), Brazil. Using a population genetics and an ethnobotany approach, the diversity and the genetic structure of cassava were evaluated. We found a total of 115 vernacular names, and in the Atlantic Forest sample the average genetic diversity (H _S = 0.654) was higher for the sweet varieties than for bitter ones (0.582). The genetic differentiation coefficient (R _ST), used to estimate the diversity among groups, was 0.057 (P < 0.001), indicating that the divergence between the two groups is low. We obtained a low correlation between the morphological and genetic distances, and the congruence was high when the ethnoclassification and the genetic structure were considered. We discuss the adaptive advantages of the sweet varieties use, the current socio-economic changes in bitter varieties use, and the ecological history of these variety groups.     

ROS-generating mitochondrial DNA mutations can regulate tumor cell metastasis

Mutations in mitochondrial DNA (mtDNA) occur at high frequency in human tumors, but whether these mutations alter tumor cell behavior has been unclear. We used cytoplasmic hybrid (cybrid) technology to replace the endogenous mtDNA in a mouse tumor cell line that was poorly metastatic with mtDNA from a cell line that was highly metastatic, and vice versa. Using assays of metastasis in mice, we found that the recipient tumor cells acquired the metastatic potential of the transferred mtDNA. The mtDNA conferring high metastatic potential contained G13997A and 13885insC mutations in the gene encoding NADH (reduced form of nicotinamide adenine dinucleotide) dehydrogenase subunit 6 (ND6). These mutations produced a deficiency in respiratory complex I activity and were associated with overproduction of reactive oxygen species (ROS). Pretreatment of the highly metastatic tumor cells with ROS scavengers suppressed their metastatic potential in mice. These results indicate that mtDNA mutations can contribute to tumor progression by enhancing the metastatic potential of tumor cells.     

Measurement of radioactivity in contaminated crops (Part 1)

It is a prerequisite to settle down how to subtract the counts based on natural radio-potassium in crops, finding out an accurate and efficient method. Considerable effort has been made so far with the investigations which have been conducted In various parts of Japan in accordance with this purpose. The writers wish to present a tentative method for measuring the radioactivity, reporting on the results obtained in comparison of this method with here-to-fore methods.