BACKGROUND AND AIMS: The maize lrt1 (lateral rootless1) mutant is impaired in its development of lateral roots during early post-embryonic development. The aim of this study was to characterize, in detail, the influences that the mutation exerts on lateral root initiation and the subsequent developments, as well as to describe the behaviour of the entire plant under variable environmental conditions. METHODS: Mutant lrt1 plants were cultivated under different conditions of hydroponics, and in between sheets of moist paper. Cleared whole mounts and anatomical sections were used in combination with both selected staining procedures and histochemical tests to follow root development. Root surface permeability tests and the biochemical quantification of lignin were performed to complement the structural data. KEY RESULTS: The data presented suggest a redefinition of lrt1 function in lateral roots as a promoter of later development; however, neither the complete absence of lateral roots nor the frequency of their initiation is linked to lrt1 function. The developmental effects of lrt1 are under strong environmental influences. Mutant primordia are affected in structure, growth and emergence; and the majority of primordia terminate their growth during this last step, or shortly thereafter. The lateral roots are impaired in the maintenance of the root apical meristem. The primary root shows disturbances in the organization of both epidermal and subepidermal layers. The lrt1-related cell-wall modifications include: lignification in peripheral layers, the deposition of polyphenolic substances and a higher activity of peroxidase. CONCLUSIONS: The present study provides novel insights into the function of the lrt1 gene in root system development. The lrt1 gene participates in the spatial distribution of initiation, but not in its frequency. Later, the development of lateral roots is strongly affected. The effect of the lrt1 mutation is not as obvious in the primary root, with no influences observed on the root apical meristem structure and maintenance; however, development of the epidermis and cortex are impaired.

• Klíčová slova
• Zea mays, lateral root, lateral root emergence, lignin, lrt1, peroxidase, root apical meristem,
• MeSH
• buněčná stěna metabolismus   MeSH
• epidermis rostlin anatomie a histologie   genetika   růst a vývoj   MeSH
• hydroponie MeSH
• kořeny rostlin cytologie   genetika   růst a vývoj   MeSH
• kukuřice setá cytologie   genetika   růst a vývoj   MeSH
• lignin metabolismus   MeSH
• meristém cytologie   genetika   růst a vývoj   MeSH
• mutace MeSH
• polyfenoly metabolismus   MeSH
• regulace genové exprese u rostlin * MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• semenáček cytologie   genetika   růst a vývoj   MeSH
• výhonky rostlin cytologie   genetika   růst a vývoj   MeSH
• vývojová regulace genové exprese MeSH
• životní prostředí MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• lignin MeSH
• polyfenoly MeSH
• rostlinné proteiny MeSH