The molecular mechanism of cotyledons in helping early maturing soybeans to adapt to high-latitude and long-day environments revealed

The molecular mechanism of cotyledons in helping early maturing soybeans to adapt to high-latitude and long-day environments revealed

The molecular mechanism of cotyledons assisting early-maturing soybeans to adapt to high-latitude long-day environments was revealed.

Recently, the Soybean Breeding Technology Innovation and New Variety Breeding Innovation Team of the Institute of Crop Science of the Chinese Academy of Agricultural Sciences systematically explained the flowering inducing function of cotyledons and their molecular basis, revealing the uniqueness of cotyledons in the adaptation of early-maturing soybean varieties to high-latitude long-day environments Role
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Related research is published online in "Plant Cells and Environment"

According to researcher Han Tianfu, the corresponding author, soybeans are typical short-day plants that originated in low- and middle-latitude regions.
However, in modern times, high-latitude and long-day regions have gradually become the main soybean producing areas in the northern hemisphere
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Existing studies have shown that mutations of flowering inhibitor genes such as E1-E4 and GmPRRs lead to reduced leaf photoperiod sensitivity, which is an important reason for the shortened growth period of soybeans and the continuous shift of planting areas to high latitudes.

In the process of using grafting technology to study the relationship between soybean roots and shoots, the team accidentally discovered that when a very early-maturing variety from the northern part of Northeast China is used as a rootstock, although only cotyledons are retained, it can still promote the flowering of late-maturing varieties under long-day conditions.
The middle-mature varieties from the Huanghuai region do not have this function when used as rootstocks
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Taking into account the special circumstances of soybean seedlings with long sunshine and short bulging days in high latitudes, the team proposed the following two speculations: the mother plants form flowering stimulating substances in short-day conditions, and are transported and stored until they are still "baby".

The team has used multiple experiments to prove that the flowering-inducing effect of cotyledons is produced after emergence, rather than inheriting the flowering stimulating substances synthesized by the parent plant and stored in the cotyledons
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After the cotyledons were unearthed and exposed to light, the "florigen" encoding gene GmFT2a was rapidly expressed at a high level, and the expression of downstream genes such as the floral meristem characteristic gene GmAP1 was up-regulated.

The researchers also created a "cotyledon plant" with cotyledons as the main photosynthetic and signal receptors by removing the stem nodes above the cotyledon nodes, and found that such plants can independently complete the entire life process of flowering and fruiting, and produce new normal Seed
.

Through the exploration of culture conditions, a model system for studying the photoperiod response mechanism of soybean and dicotyledonous plants based on "cotyledon plants" has been established

The research results have certain guiding significance for the early maturity breeding and cultivation of short-day crops such as soybeans in high-latitude and long-day areas
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(Source: Wang Fang, China Science News)

Related paper information: https://doi.

https://doi.
org/10.
1111/pce.
14120