Temperature is an important environmental factor that affects
the growth and development of plants. However, temperature
varies within a growth cycle and crop species seldom complete
their growth cycle under optimum temperature (Moriondo et al.,
2011). Summer crops often face the problem of supra-optimal tem-
perature, which is among the most damaging abiotic stresses and
causes significant changes in plant architecture due to fine tuning
of leaf and petiole inclination (Van Zanten et al., 2009). More-
over, temperature modifies leaf orientation by affecting tissues in
the pulvinal region resulting in active heliotropic movements in
response to air temperature (Lang and Begg, 1979; Bielenberg et al.,