TY - JOUR
T1 - Class i KNOX genes are associated with organogenesis during bulbil formation in Agave tequilana
AU - Abraham-Juárez, María Jazmín
AU - Martínez-Hernández, Aída
AU - Leyva-González, Marco Antonio
AU - Herrera-Estrella, Luis
AU - Simpson, June
N1 - Funding Information:
We are grateful to Dr Octavio Martínez de la Vega for bioinformatic support, Dr Stefan de Folter and Dr Nayelli Marsch for providing the KNAT1 overexpression line and for helpful advice on analysis of A. thaliana lines, Aurora Verver for help with the histological analysis, and Ilenia Renteria for advice on in situ hybridization. MJA-J and MAL-G are indebted to CONACyT Mexico for PhD fellowships (191408 and 176135), and this work was supported by grants from Fondos Mixtos from Guanajuato State, Mexico GTO-04-C02-143 and by grants from ‘Fideicomiso no. 167304 para la investigación científica y desarrollo tecnológico del centro público Colegio de Postgraduados’.
PY - 2010/9
Y1 - 2010/9
N2 - Bulbil formation in Agave tequilana was analysed with the objective of understanding this phenomenon at the molecular and cellular levels. Bulbils formed 14-45d after induction and were associated with rearrangements in tissue structure and accelerated cell multiplication. Changes at the cellular level during bulbil development were documented by histological analysis. In addition, several cDNA libraries produced from different stages of bulbil development were generated and partially sequenced. Sequence analysis led to the identification of candidate genes potentially involved in the initiation and development of bulbils in Agave, including two putative class I KNOX genes. Real-time reverse transcription-PCR and in situ hybridization revealed that expression of the putative Agave KNOXI genes occurs at bulbil initiation and specifically in tissue where meristems will develop. Functional analysis of Agave KNOXI genes in Arabidopsis thaliana showed the characteristic lobed phenotype of KNOXI ectopic expression in leaves, although a slightly different phenotype was observed for each of the two Agave genes. An Arabidopsis KNOXI (knat1) mutant line (CS30) was successfully complemented with one of the Agave KNOX genes and partially complemented by the other. Analysis of the expression of the endogenous Arabidopsis genes KNAT1, KNAT6, and AS1 in the transformed lines ectopically expressing or complemented by the Agave KNOX genes again showed different regulatory patterns for each Agave gene. These results show that Agave KNOX genes are functionally similar to class I KNOX genes and suggest that spatial and temporal control of their expression is essential during bulbil formation in A. tequilana.
AB - Bulbil formation in Agave tequilana was analysed with the objective of understanding this phenomenon at the molecular and cellular levels. Bulbils formed 14-45d after induction and were associated with rearrangements in tissue structure and accelerated cell multiplication. Changes at the cellular level during bulbil development were documented by histological analysis. In addition, several cDNA libraries produced from different stages of bulbil development were generated and partially sequenced. Sequence analysis led to the identification of candidate genes potentially involved in the initiation and development of bulbils in Agave, including two putative class I KNOX genes. Real-time reverse transcription-PCR and in situ hybridization revealed that expression of the putative Agave KNOXI genes occurs at bulbil initiation and specifically in tissue where meristems will develop. Functional analysis of Agave KNOXI genes in Arabidopsis thaliana showed the characteristic lobed phenotype of KNOXI ectopic expression in leaves, although a slightly different phenotype was observed for each of the two Agave genes. An Arabidopsis KNOXI (knat1) mutant line (CS30) was successfully complemented with one of the Agave KNOX genes and partially complemented by the other. Analysis of the expression of the endogenous Arabidopsis genes KNAT1, KNAT6, and AS1 in the transformed lines ectopically expressing or complemented by the Agave KNOX genes again showed different regulatory patterns for each Agave gene. These results show that Agave KNOX genes are functionally similar to class I KNOX genes and suggest that spatial and temporal control of their expression is essential during bulbil formation in A. tequilana.
KW - Agave tequilana
KW - Arabidopsis transformation
KW - KNOX genes
KW - bulbils
KW - cDNA libraries
KW - in situ hybridization
KW - meristems
UR - http://www.scopus.com/inward/record.url?scp=77956581645&partnerID=8YFLogxK
U2 - 10.1093/jxb/erq215
DO - 10.1093/jxb/erq215
M3 - Article
C2 - 20627900
AN - SCOPUS:77956581645
SN - 0022-0957
VL - 61
SP - 4055
EP - 4067
JO - Journal of Experimental Botany
JF - Journal of Experimental Botany
IS - 14
ER -