The Responses To Photoperiod Variation And The Clone And Expression Analysis Of EMF-like Gene In Maize

Tropical and subtropical germplasm contains abundent hereditary variation. However, photosensitivity is the main restriction of its use in temperate zone. We have to study it in order to utilize tropical and subtropical germplasm better. We studied the responses to photoperiod in maize and cloned a photoperiod-related gene which play a major role during the transition from vegetative growth to reproductive growth. The main results are as follows:1. CML288,a tropical inbred line and Huanzao4,a temperate inbred line were used as materials to study the responses to photoperiod variation in maize. The two inbred lines were grown in 2 different controlled photoperiod rhythms, 9hr and 15 hr. Result showed that Huangzao4 can perform vegetative growth and reproductive growth both on short-day conditon and long-day condition. While CML288 could only grow in vegetative phase, not flower on long-day condition. This means that CML288 is very sensitive to photoperiod variation but Huangzao4 isn't.2. CML288 plants grew in one level of photoperiod and then were transferred to the other photoperiod level when they were in different stages. Developmental stages and leaf numbers were recorded. Seven-leaf stage is the most sensitive period for CML288 on short-day condition, and nine-leaf stage on long-day condition.This period is exactly between the formation of spikelet and floret, leaf number, Days to tasselling, to pollen shadding, to silking and ASI can be used as index to evaluate Photosensitivity in maize.3. A photoperiod related gene was cloned using RT-PCR and was named as EMF-like gene (Accession number: DQ343238). EMF-like gene contains an open reading frame of 1881bp encoding a putative transcription factor of 626 amino acids, which possessed of a C2H2-type zinc finger motif, two putative nuclear localization signals and an acidic cluster.It may be function as a transcription factor.4. Expression analysis of EMF-like gene using RT-PCR in different treated materials was performed. It expressed or didn't differ from different materials. Northern blot revealed that it expresses both in the SAM and leaf. The function of the gene might be maintained vegetative development by repressing the flower program genes.