Low temperature is the main reason for the economic losses in pepper
(Capsicum annuum) global production. Cold-related genes regulated by
abscisic acid (ABA) have already been identified in previous studies,
including the CaMBF1, a gene homologous to potato MBF1 (StMBF1) encoding the
coactivator multiprotein bridging factor 1. The study focused on the
characterization of the CaMBF1 from pepper and its role on abiotic stress
tolerance.

CaMBF1 was expressed in all tested pepper plant tissues, especially in
flowers and seeds. The expression of CaMBF1 in pepper seedlings was highly
suppressed by several stresses including high salt and heavy metal stresses.
When CaMBF1 was overexpressed in Arabidopsis, the damages of cold stress in
the seedlings worsened. Moreover, the germination, cotyledon greening and
lateral root formations were more severely affected by salt stress in
transgenic Arabidopsis lines compared with wild-type plants.

Arabidopsis transgenics overexpressing CaMBF1 exhibited reduced cold and
high salt stress tolerance during seed germination and post-germination.
This indicates that CaMBF1-overexpressing Arabidopsis plants were
hypersensitive to stresses. These knowledge of CaMBF1 will be useful for
genetic engineering of more novel varieties in the future.

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