A Novel Endo-β-Mannanase Gene in Tomato LeMAN5 Is Associated with Anther and Pollen Development

• Published in: Plant physiology (Bethesda) 2004-03, Vol.134 (3), p.1080-1087
• Main Authors: FILICHKIN, Sergei A, LEONARD, Jeffrey M, MONTEROS, Alvaro, LIU, Po-Pu, NONOGAKI, Hiroyuki
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Anthers; Arabidopsis - genetics; Base Sequence; Biological and medical sciences; Cell walls; Complementary DNA; Development and Hormone Action; DNA, Complementary - genetics; DNA, Plant - genetics; Economic plant physiology; Flowering, floral biology, reproduction patterns; Fundamental and applied biological sciences. Psychology; Genes, Plant; Genes. Genome; Growth and development; Lycopersicon esculentum; Lycopersicon esculentum - enzymology; Lycopersicon esculentum - genetics; Mannosidases - genetics; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Plants; Plants, Genetically Modified; Pollen; Pollen - growth & development; Polymerase chain reaction; Promoter regions; Promoter Regions, Genetic; RNA; RNA, Messenger - genetics; RNA, Plant - genetics; Seeds; Transgenic plants
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.103.035998

Endo-β-mannanase (EC 3.2.1.78) is involved in cell wall disassembly and the weakening of plant tissues by degrading mannan polymers in the cell walls. Endo-β-mannanase genes are expressed in tomato (Lycopersicon esculentum) seeds (LeMAN1 and LeMAN2) and fruits (LeMAN3 and LeMAN4). A novel endo-β-mannanase gene (termed LeMAN5) was found in the tomato genome by genome-walking PCR and bacterial artificial chromosome library screening. The 5′-upstream region of this endo-β-mannanase gene contained four copies of the pollen-specific cis-acting elements POLLEN1LELAT52 (AGAAA). A GUS-reporter gene driven with the putative LeMAN5 promoter (-543 to +38) was activated in anthers and pollen of transgenic Arabidopsis, with the highest β-glucuronidase activity detected in pollen. β-Glucuronidase expression was detected in mature pollen retained in sporangia, discharged pollen, and elongating pollen tubes in transgenic Arabidopsis. Consistently, expression of LeMAN5 mRNA and endo-β-mannnanase activity was detected in tomato anthers and pollen. In anthers, the highest mRNA expression and endo-β-mannanase activity were detected during late stages of anther development, when pollen maturation occurred. Endo-β-mannanase activity was present in discharged pollen, which was easily eluted in a buffer, indicating that the enzyme proteins are probably secreted from, and deposited on, the surface of pollen. These data suggest that the LeMAN5 endo-β-mannanase is associated with anther and pollen development.