Long photoperiod affects the maize transition from vegetative to reproductive stages: a proteomic comparison between photoperiod-sensitive inbred line and its recurrent parent

Maize (Zea mays L.) is a typical short-day plant that is produced as an important food product and industrial material. The photoperiod is one of the most important evolutionary mechanisms enabling the adaptation of plant developmental phases to changes in climate conditions. There are differences in the photoperiod sensitivity of maize inbred lines from tropical to temperate regions. In this study, to identify the maize proteins responsive to a long photoperiod (LP), the photoperiod-insensitive inbred line HZ4 and its near-isogenic line H496, which is sensitive to LP conditions, were analyzed under long-day conditions using isobaric tags for relative and absolute quantitation. We identified 5259 proteins in maize leaves exposed to the LP condition between the vegetative and reproductive stages. These proteins included 579 and 576 differentially accumulated proteins in H496 and HZ4 leaves, respectively. The differentially accumulated proteins (e.g., membrane, defense, and energy- and ribosome-related proteins) exhibited the opposite trends in HZ4 and H496 plants during the transition from the vegetative stage to the reproductive stage. These results suggest that the photoperiod-associated fragment in H496 plants considerably influences various proteins to respond to the photoperiod sensitivity. Overall, our data provide new insights into the effects of long-day treatments on the maize proteome, and may be useful for the development of new germplasm.