Leptosphaeria maculans, a pathogen of Brassica napus, is unable to invade most wild-type accessions of Arabidopsis thaliana, although several mutants are susceptible. The infection pathway of L. maculans via a non-invasive inoculation method on A. thaliana lms1 (undefined), pmr4-1 (defective in callose deposition), and pen1-1 and pen2-1 (defective in non-host responses to several pathogens) mutants is described. On wild types Col-0 and Ler-0, hyphae are generally arrested at stomatal apertures. A T-DNA insertional mutant of L. maculans (A22) that penetrates stomatal apertures of Col-0 and Ler-0 five to seven times more often than the wild-type isolate is described. The higher penetration frequency of isolate A22 is associated with an increased hypersensitive response, which includes callose deposition. Complementation analysis showed that the phenotype of this isolate is due to T-DNA insertion in an intronless gene denoted as ipa (increased penetration on Arabidopsis). This gene is predicted to encode a protein of 702 amino acids with best matches to hypothetical proteins in other filamentous ascomycetes. The ipa gene is expressed in the wild-type isolate at low levels in culture and during infection of A. thaliana and B. napus.

Leaf litter is an organic waste that can be degraded biologically in nature. Based on the previous research, mahogany trees in Universitas Negeri Semarang (UNNES) campus produce about 10 ton ha−1 leaf litter in campus forest area and 2.5 ton ha−1 along campus street within three-month-period. By this abundant amount of leaf litter, it is quite difficult to overcome the problem of litter management. Therefore, the idea of leaf litter utilization as a raw material of biocomposite is promising to reduce the use of wood as an important commodity of human needs. However, the characterization of leaf litter feasibility for biocomposite production has not been done. This research aims to characterize the physicochemical properties of mahogany leaf litter. Leaf litter was oven-dried for 5 h at 50 °C and then was ground using a mechanical blender to obtain leaf litter powder. Then, the proximate (moisture, proteins, fat and carbohydrate content) and Fourier transform infrared spectroscopy (FTIR) analysis were performed. The results show that the content of crude ash is 9.90 ± 0.65%; crude protein content 24.83 ± 0.79%; crude fat content 11.37 ± 1.05%; volatile compound 65.14 ± 4.77%; charcoal content 7.66 ± 0.71%; and moisture content 6.61 ± 0.69%. The FTIR spectrum shows that leaf litter has low water content and indicates the content of phenolic compounds such as flavonoid. The physic-chemical properties of mahogany leaf litter indicate that mahogany leaf litter is suitable to be used as the decay resistance of biocomposite material.

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